Planing under sail vs power

[djtil]

I am building Iain Oughtred's Fulmar, a dingy type sailboat 16'8" x 5'10", draft 6". It is a design that will apparently plane under the right conditions.

The question is, if a boat will plane under sail, can it also plane under power? If so, what would it take to achieve this with this boat? I am not looking for great speed, just something above displacement speed. I really do not want to just hang an outboard on, too ugly. Obviously light weight, appendage drag, and weight placement would all be critical. Any help would be greatly appreciated.

http://i621.photobucket.com/albums/tt298/djtil_photos/Fulmar-1LinesPlan-1.jpg

[Thorne]

I really do not want to just hang an outboard on, too ugly. Obviously light weight, appendage drag, and weight placement would all be critical.

So are you considering an inboard, or flying a big kite, being towed by a powerboat, or?? What exactly are we talking about here?

[Hwyl]

I'd say hanging an outboard on the back is your only choice

[JimD]

The question is, if a boat will plane under sail, can it also plane under power? If so, what would it take to achieve this with this boat?

It would take a power source that mimics the force of the sail. Ie, sails tend to drive the bow down and raise the stern. Propellors tend to raise the bow and squat the stern.

[djtil]

Some sort of inboard power. Maybe similar to this:

http://i621.photobucket.com/albums/tt298/djtil_photos/BOBDrive1.jpg
Or, maybe a small jet drive like this: http://www.belljar.net/boats/jetboatdevel1.htm

[Hwyl]

What happens when you capsize, or do you intend to use it purely as a power boat?

[john welsford]

One of the critical factors in making a sailing boat plane, is weight. Adding an engine adds weight, lots of it ( comparitively) and that in realistic terms makes a project like this very difficult. I doubt that Fulmar will work. I think that you are likely to get a better result tweaking a planing power boat hull so it will sail after a fashion than doing it the other way around.

If you want to see what sort of compromises are needed to produce a boat that will plane under power and under sail, have a look at those odd looking Macgregor trailerable yachts ( I'm sure google can find them for you)

JohnW

[Mike Vogdes]

I would build the boat as designed first, then verify it actually planes under sail befor getting involved in strapping an engine on, or in it.. Might be one of those deals where it will plane in near gale force winds, running downhill and sailed by a 60lb little girl.

[Hwyl]

If I remember it closely resembles a big Albacore, and Albacores plane well, Mr Oughtred sails performance boats himself, so he knows what he's talking about.

[djtil]

First of all, thank you for the replies.

No, I am not trying to go where Macgregor has gone before. :eek:

I do not want to compromise the sailing performance significantly, although I am not planning on racing. More interested in relaxed family daysailing and maybe overnight beach cruising on inland lakes. So more like sail with auxillary. Planing under power would seem not realistic.

Assuming weight of under 50 lbs. under rear seat/deck, how adversely would this affect sailing performance.

[JimConlin]

...
Assuming weight of under 50 lbs.

Questionable assumption. A 5HP (4-stroke) outboard, with a 3 gallon fuel tank, weighs about 85 lbs. Add the weight of the structural reinforcement to take the outboard.
With the extra 100+ lbs, planing under sail will be a fond memory.

[Hwyl]

Questionable assumption. A 5HP (4-stroke) outboard, with a 3 gallon fuel tank, weighs about 85 lbs. Add the weight of the structural reinforcement to take the outboard.
With the extra 100+ lbs, planing under sail will be a fond memory.

I agree with Jim, and as soon as you get some water in the boat, the engine will be a fond memory.

I have seen both Fireflies and GP 14's with outboards, the rigs shake like crazy, once you get up to speed.

J22's go really fast with a 4HP outboard, with their hull shape it's difficult to define planing..

[TerryLL]

James McMullen has a Fulmar and hopefully he will be along shortly to share his thoughts. He has posted some comments about his Fulmar on the Caledonia Yawl forum that you might find interesting. Here's the link:

http://www.mavc2002.com/cyforum/viewtopic.php?f=6&t=746

[djtil]

So what are my options for auxillary power?

The overnight camp cruising I would like to do is on Lake Winnebago here in Wisconsin. The weather and lake conditions can be pretty variable and somewhat unpredictable. Hence the desire for some speed under power. The campground about 18 miles from my launch point. I would like to make it home if there is no wind for the return leg.

[George Roberts]

Perhaps some type of liquid fuel rocket placed below the waterline amidships. A bit of upward thrust would balance the excess weight.

[Thorne]

So what are my options for auxillary power?


An outboard. Make the bracket removable if you don't want to see it all the time.
http://www.boatsnbits.co.uk/acatalog/outboardbracket_Lge.JPG

[TerryLL]

A reasonable option here might be the air-cooled Honda 2HP. It weighs in at 27 pounds. Probably not enough power to plane a Fulmar, but it'll push it at hull speed, which is the speed you'd be going most of the time with decent wind.

[James McMullen]

Yes, I've got a a Fulmar. She planes just great under sail. You said that you're more interested in relaxed family daysailing than racing though. . . . .are you sure you want a Fulmar?

Putting an inboard in her would absolutely wreck her for fast sailing. If you wanted to plane her under power with just a couple of people aboard, then you would probably need to hang about a 20hp outboard off the transom--which would absolutely wreck her for fast sailing.

Why do you think you need a planing motorboat anyways? If you had one of those little 2hp Hondas or something for an auxilliary, then you could have a perfectly decent sailboat with a safe, economical lightweight get-home engine. Thinking you need speed under power to make you safer is totally fallacious. What you need to make you safe is good judgement and seamanship, and adding horsepower won't help with either of those. You simply need too big and too heavy of a motor to make her into a planing powerboat for it to be workable.

I would definitely reccommend a Caledonia Yawl or one of Welsford's Navigators or Pathfinders over a Fulmar if you are looking for a family camp-cruising sailboat. The Fulmar is better left as a fast day sailboat.

[Tom Lathrop]

No matter what you do, 18 miles is going to prove a real problem. Sail or power, planing or not, 18 miles is too far as a regular thing in addition to whatever you may want to do. Planing in a small sailboat is a sometime thing anyway. Many get through a season without planing more than a couple times. Match that with the fact that the wind will seldom let you plane in the direction you want to go and 18 miles will often take up most of the day. A small and light 2 stroke motor will probably plane your Fulmar, if it is balanced well, but not very fast.

[djtil]

Too late to change designs.




http://i621.photobucket.com/albums/tt298/djtil_photos/latestpictures084.jpg

Would not an outboard hanging off a bracket be at least if not more detrimental to sailing than a similar weight inboard setup? Plus, I'm not fond of the idea of wrestling with getting it on and off, especially not if on the water. Are they any less susceptible to damage in the event of a capsize?

I am fine with not planing under power, as it seems unreasonable.

[djtil]

Tom-

I agree, 18 miles is a long way. The idea is to do over a weekend. Saturday sail out, camp overnight, Sunday sail back. Am I dreaming?

[johnw]

The shaft and prop will add enough drag that it will substantially slow the boat under sail. 2 hp outboard looks like the best option. At hull speed, that's about 3 1/2 hours to go 18 miles. Get an early start.

[djtil]

The shaft and prop will add enough drag that it will substantially slow the boat under sail.

I agree, which is why I was hoping for a retractable drive or a small jet drive.

[kenjamin]

Although the Fulmar is light and has a bit of a flat run of the bottom near the stern that allows her to plane well under sail, the problem is that under motor alone you would be missing the force of the sail to help keep the bow down and she would no longer be light enough to plane as easily as others have said. Go look at pictures of the Goat Island Skiff under motor alone and like most sail boats with rockered bottoms you can see that the rocker of the bottom forces the bow high under power. Or find a rocking chair and push it hard from the tail end of the rockers and it's the same deal. If you're lucky the rocking chair will move forward before the front of the chair rises up and the chair falls backwards on you. Now you could move the weight of the motor forward to help keep the bow down but it would still take quite a bit of power to make it plane and the stability once on a plane would be a lot more exciting than you or your family would want to experience.

I think the two horse Honda would be perfect for this boat but be careful how you store it – four strokes are sensitive to the position they are stored.

If you need to move your family quickly and efficiently over 18 miles then you might consider something like a Nexus planing dory for your next build.

http://ford.physics.fsu.edu/nexus planing.jpg

[Hwyl]

An outboard can be left off on the good sailing days, and I bet that would be most days. The boat looks great BTW.

[rbgarr]

Seven to eight hours of a whining outboard motor each weekend to travel 36 miles? Sounds hellish.

[Thorne]

You get used to sailing the boat with the outboard latched up at an angle so the prop and shaft clear the water -- biggest issue is snagging sheets on the prop.

Here's a Navigator sailing that way -
http://www.jwboatdesigns.co.nz/plans/navigator/nav.jpg

[Hwyl]

It would be easy to go more that hull speed with an outboard. 8 knots would be easily attained I bet. !8 miles is a good haul though.
I don't agree that the boat would not plane under power, but it would not be a nice ride.

[john welsford]

This layout, using a rise and fall bracket of the type often used for trolling motors on power boats is the most common solution among my customers, and they report that in most cases a 2 hp motor will satisfactorily push a loaded 17 1/2 ft Pathfinder which is a lot bigger boat than a Fulmar. I agree with the comment on the 2HP Honda, I had one and it was the best small engine I have ever used, it had more push than the 2 strokes, less smoke and vibration, started easily and was extremely economical.

JohnW

You get used to sailing the boat with the outboard latched up at an angle so the prop and shaft clear the water -- biggest issue is snagging sheets on the prop.

Here's a Navigator sailing that way -
http://www.jwboatdesigns.co.nz/plans/navigator/nav.jpg

[W Grabow]

I used to put a 1.5 hp air-cooled outboard on this skiff. It would easily go at hull speed, and I think that more hp would have made it quicker. The drawback was the exhaust noise. http://photos1.blogger.com/blogger/1410/2906/1600/Panama%20skiff2%20001.jpg

[Tom Lathrop]

Tom-

I agree, 18 miles is a long way. The idea is to do over a weekend. Saturday sail out, camp overnight, Sunday sail back. Am I dreaming?

I should have thought of that obvious schedule. 18 miles is certainly doable. Having a lightweight Honda 2hp on the stern is no big deal and may use them on small sailboats. One thing you wil find is that the tiny tank will not take you very far toward the 18 mile goal so refilling underway is a real possibility. That engine probably does not have a fuel pump so a remote tank may not be possible. Forget about any inboard on a Fulmar. That is the way to real nuisance problems.

The little 2hp can be called on when its directly upwind and wind is light. Motor sailing can be a possibility. In any case, you may need the assurance of getting back to work if the wind is dead. The motor can be left at camp when not needed.

[djtil]

Again, thanks to all who have taken the time to reply.

As far as crew, daysailing would be my wife and I and possibly one or more LARGE kids. The camping trips would just be my wife and I. Novice sailors all.

There are also launch point closer to the campground than 18 miles, but they are not as convienient or well appointed.

I am not totally opposed to an outboard. In fact I have previously purchase an Evinrude folding 3 hp. The only long shaft one I have ever seen. I was hoping to be able to fold the leg up while sailing instead of having to jack up or stow the engine. I was just hoping for a more elegant solution. But I understand the benefits of simplicity.

Forgetting about speed, any thoughts about the small jet drive as an auxillary?

[Philip Maynard]

I put an inboard 5hp 4 stroke under the seat of a 15'8" boat and it will plane under sail but not under power, but the engine can push it well into a headwind. I do not know what it weighs but it's much less than 85#. 7x4 prop, direct drive. I like it because it's out of the way and no outboard hanging off the back, I have never flipped the boat, it's noisy, I'd never regularly plan on long powered stretches. The dingy bailer drains water better under sail than power.
http://www.pmaynard.lunarpages.com/index_files/image030.jpg
http://www.pmaynard.lunarpages.com/index_files/cerlew-rudder-1.JPG

[djtil]

Just when I'm ready to go with the flow, along comes Philip with what looks to be a successful example of the solution I was hoping for. Granting you won't achieve plane under power, yet an inboard setup that does not destroy sailing performance. Are there other downsides?

[Woxbox]

Looks like a beautiful job on the boat and exciting plans. I'll predict here and now that you'll find that setting a destination at the maximum distance you can cover in a day is a mistake.

All cruising, whether in a dinghy or a big yacht, is far, far more enjoyable if there's lots of time to spare. That what makes it genuinely relaxed. It took me years to figure this out. As my boats got bigger, I set out to cover longer stretches each day. But which days are most memorable as happy cruises with friends and family? Always those that covered half the ground possible. It just sets the tone for a good day. See something interesting along the way? Just stop and look awhile. Wind dies down? No sweat, there's only a few miles to go. Somebody wants to stop and swim? Time for that, too. And so on and so on.

Ambitious schedules are good for you alone or with an equally ambitious buddy, but the family won't appreciate it and it could poison the whole boating thing right from the start.

[rbgarr]

As far as crew, daysailing would be my wife and I and possibly one or more LARGE kids. The camping trips would just be my wife and I. Novice sailors all.

There are also launch point closer to the campground than 18 miles, but they are not as convienient or well appointed.

Forgetting about speed, any thoughts about the small jet drive as an auxillary?

I've seen jetskis used as tow boats for small sailboats (like a string of Optimist prams). They don't steer very well at low speeds but for a straightline pull, it might work. Your kids might enjoy zipping around in the distance while you and your wife enjoy sailing.

[Woxbox]

Edey and Duff made a few Dovekies with jet ski type auxiliaries. The main goal was to retain the extreme shoal draft capability of the flat-bottomed boat. They were never entirely happy with the results, but I don't know exactly why.

[Brian Palmer]

Jets are generally less efficient than props. Around here, a lot of folks fit jets to their outboards so they can run up on plane in a few inches of water on the Susquehanna to get over the bars and rapids for fishing. The jet replaces the lower unit, and (I have read) they are generally about 15% less efficient; that is, fitting a jet pump to a 100 hp outboard is equivalent to running an 85 hp outboard with a prop.

Brian

[Scott Rosen]

Simple is best.

Retrofitting an inboard in a boat not designed for it could create problems not only with performace but structural problems too. An inboard puts entirely different stresses on a hull.

Same with an outboard. The transom may not be designed to handle the force of an outboard strong enough to make the boat plane.

I think it's a fool's errand to try find a way to make her plane under power.

Use the small outboard you already have for a season or two. By then you'll have a better idea of what you need and what's realistic.

No single design does everything well.

[Thorne]

Forgetting about speed, any thoughts about the small jet drive as an auxillary?

Won't work well 'cause it if did you'd see lots of 'em. No need to reinvent the wheel here unless you really really need to go there.

See the WB article on installing a jetski unit in a cleverly-designed hull, result looked like a stock lobstah boat but hull was significantly different. Not for the faint of heart, thin of wallet, or use in a sailing hull design.

http://www.woodenboat.com/img_mags/WB198_CoverSpread.jpg

[djtil]

Once again, thank you for all the replies.

As to using a trolling motor as an auxillary, I had also started down that path once. I bought a 12v Navigator engine mount motor, 35 lbs thrust. I really don't like the idea of just hanging something on the transom, so I was working on some kind of retractable mount. There were several threads about rudder mounted motors, etc. One big concern became the range acheivable. Batteries can be added, but then there goes the weight and sailing performance. Yes/No?

One thing to remember at this point is that I am no longer aiming for planing speeds under power. What I am looking for is auxillary power to get me in to camp or home from some distance if the wind dies. I would like to accomplish this with the minimum loss of sailing performance. Also this is a light open boat, so I am not thinking about anything big or powerful. Small and light, probably 4-6 hp. So jetski setups are overkill.

The link I posted above http://www.belljar.net/boats/jetboatdevel1.htm (http://www.belljar.net/boats/jetboatdevel1.htm) is one guy's attempt to use a 5 hp commercial water pump to power a small boat. He was able to acheive approximately 5 mph with his cobbled together setup (check out the geysers). Something along this line is what I am still considering. Thoughts?

[tprice]

Questionable assumption. A 5HP (4-stroke) outboard, with a 3 gallon fuel tank, weighs about 85 lbs. Add the weight of the structural reinforcement to take the outboard.
With the extra 100+ lbs, planing under sail will be a fond memory.
I don't know about that. 16' dinghies usually sail with 2 crew and plane just fine. If he put a 9 hp (less weight than the crew) on the transom and was singlehanding, I'll bet it would plane, despite the poor planing hull shape.
If you wanted a sailing boat that could also plane under outboard power, I'd think a better (planing hull form) choice of hull design is the place to start.

[johnw]

Once again, thank you for all the replies.

As to using a trolling motor as an auxillary, I had also started down that path once. I bought a 12v Navigator engine mount motor, 35 lbs thrust. I really don't like the idea of just hanging something on the transom, so I was working on some kind of retractable mount. There were several threads about rudder mounted motors, etc. One big concern became the range acheivable. Batteries can be added, but then there goes the weight and sailing performance. Yes/No?

One thing to remember at this point is that I am no longer aiming for planing speeds under power. What I am looking for is auxillary power to get me in to camp or home from some distance if the wind dies. I would like to accomplish this with the minimum loss of sailing performance. Also this is a light open boat, so I am not thinking about anything big or powerful. Small and light, probably 4-6 hp. So jetski setups are overkill.

The link I posted above http://www.belljar.net/boats/jetboatdevel1.htm (http://www.belljar.net/boats/jetboatdevel1.htm) is one guy's attempt to use a 5 hp commercial water pump to power a small boat. He was able to acheive approximately 5 mph with his cobbled together setup (check out the geysers). Something along this line is what I am still considering. Thoughts?

Sounds not particularly efficient. Perhaps you could borrow a 2 hp motor and try it. I think anything bigger is overkill.

There are setups that allow you to removed the outboard bracket while sailing. You could also build a well, although I don't like them.

If you set a less ambitious schedule for distance covered, rowing would be an option. You'd only do it in no wind, and it's good for you and not nearly as noisy. And even if you work up a sweat, it will smell better.

[Thorne]

I'm afraid that no matter how many times you ask the question, the answer remains the same -- outboard or oars for lightweight aux power, batteries and trolling motor or small inboard for heavier aux power. The heavier options won't really work for your hull and described use.

You don't really think that we will discover something previously unknown to mankind on this thread, do ya? If not, then just go with what everyone else on the planet uses. Can't give you my thoughts any plainer than that.

[Tom Lathrop]

Has anyone who advocates electric power for this use actually calculated how much battery would be required for this? I'll bet not. Even at slow speed, and anything faster will multiply the needs.

It just ain't practical to go 18 miles at any reasonable speed, not to mention getting 18 miles back. Against any decent wind, forget it. There is an electric boat race in conjunction with the Mid Atlantic Small Boat Festival at at St Michaels and the best of these dedicated electric boats won't do what is being asked for here.

As Thorne says, a small 2-3hp outboard is the only practical answer other than oars and, at 36 miles over two days, oars don't sound practical either.

[patrick.blanchard]

Woxbox, your insight is refreshing, thanks.

What has not been mentioned here is planing with a following sea. This is what is partially appealing for double enders; the hull transfers complex wave vector forces into somewhere between up and forward vectors. Dumas calles it 'surfing'. Surfers call it 'shooting the tube' I think.

There is no way in thunder I would consider doing such a stunt in a boat unless the only other option would be to step up to the life raft. I would probably heave to instead. This is all just theory to me really, because I've never done either.

Looks like a beautiful job on the boat and exciting plans. I'll predict here and now that you'll find that setting a destination at the maximum distance you can cover in a day is a mistake.

All cruising, whether in a dinghy or a big yacht, is far, far more enjoyable if there's lots of time to spare. That what makes it genuinely relaxed. It took me years to figure this out. As my boats got bigger, I set out to cover longer stretches each day. But which days are most memorable as happy cruises with friends and family? Always those that covered half the ground possible. It just sets the tone for a good day. See something interesting along the way? Just stop and look awhile. Wind dies down? No sweat, there's only a few miles to go. Somebody wants to stop and swim? Time for that, too. And so on and so on.

Ambitious schedules are good for you alone or with an equally ambitious buddy, but the family won't appreciate it and it could poison the whole boating thing right from the start.

[john welsford]

As I see it, our man is concerned about getting his family home if it blows up. If the wind is a tailwind or a reach thats not an issue as he can slide along under reduced sail. To windward with a light sailing boat speed will be very limited as pounding into a chop pushed by a motor at any speed in a sailing boat hull is both uncomfortable and wet.
Can I suggest that motorsailing under well reefed sail with the 2 or 3 hp motor running gently is much more effective than most people realise. Please dont ruin that nice boat with a motor inside, but think in terms of mounting an outboard in such a way as to keep the prop in the water when the boats heeled a bit. Thats usually a rise and fall bracket as close to the centerline as possible without restricting the rudder movement.

JohnW




Has anyone who advocates electric power for this use actually calculated how much battery would be required for this? I'll bet not. Even at slow speed, and anything faster will multiply the needs.

It just ain't practical to go 18 miles at any reasonable speed, not to mention getting 18 miles back. Against any decent wind, forget it. There is an electric boat race in conjunction with the Mid Atlantic Small Boat Festival at at St Michaels and the best of these dedicated electric boats won't do what is being asked for here.

As Thorne says, a small 2-3hp outboard is the only practical answer other than oars and, at 36 miles over two days, oars don't sound practical either.

[johnw]

Yes, it's quite surprising how much better a boat goes under even a little push from the sails when you're motorsailing. And since you have the speed not to stall the centerboard or keel, you can sail surprisingly close to the wind.

[rbgarr]

The long shaft Evinrude 3 should serve quite well for motorsailing.

[mcdenny]

I can shed some light on the E power numbers: Assuming 16' lwl; 800 # for boat and crew; 250# for (4) 105 ah 12v batteries and 50# for motor, controller, charger, etc you could go 5 mph for 16 miles. The electric bits would cost about $3000. Batteries could be mounted along side the center board increasing stability and decreasing legroom. You'd have to drag a 10" or 12" dia prop to get efficiency, sailing would suffer.

A trolling motor and one 40# battery would be good for in and out of the launching ramp and would probably take you as far as I could row a Fulmar.

BTW, my spreadsheet indicates it will take 1.3 hp to go 5 mph with an all up weight of 1100#

A 2 hp Honda weighs 27#, costs around $800; a 2.5 Suzuki weighs 30# (and has neutral and is water cooled - quieter, I'd bet) and costs maybe $700.

As a dedicated electric boat builder, I think a tiny gas OB is the only remotely practical solution to getting back home 18 miles away on schedule.

How about trailering the boat to the destination, go for a nice sail as far as the wind allows Sat and Sun, camp overnight and trailer it home?

It's a beautiful boat by the way - congrats.

[djtil]

Once again thanks for all the replies.

I bow to the collective wisdom of those with more experience (virtually everyone) than I. Since I already have the Evinrude, I will use that as auxillary power for now. "Now" being whenever I can actually finish the boat and go sailing. Once I have some miles under me, I'm sure I will be able to more fully appreciate all your comments.

This has been a very good "thinking chair" excersize for me, as life (kitchen remodeling in this case) has once more interrupted my boatbuilding. It is going on five years since I started the build. When I have time, I will post some more build pictures. It has been fun if frustrating at times. So far I am happy with the results. I have not made any irreparable blunders yet, so I will consider this another blunder avoided.

[Scott Rosen]

Before you get a new outboard, you may want to make sure that you get one with enough power. Two hp might be enough, but I'm not sure. You want an engine strong enough to get you home with a full crew, against a strong headwind, into a steep chop. To round out the picture, figure your wife will be puking over the side and your kids screaming, so you'll want to make headway. Since you're lake sailing you don't have to add the additional burden of bucking the tide.

Then there's the bad days . . .

[paladin]

For years I used a little 2 hp evinrude yachtwin on a 31 foot boat.......then I upgraded...to a 4 1/2 Hp Seagull......

[kenjamin]

Please don't try this at home unless you have a very good machinist for a very good friend:

1)make a round template
http://ford.physics.fsu.edu/Xena6236.jpg

2) draw a round circle on the bottom of your boat
http://ford.physics.fsu.edu/Xena6241.jpg

3) cut out the circle
http://ford.physics.fsu.edu/Xena6372.jpg

4) encircle the round hole in the boat with a live well and plug the hole with a 1/2" thick lexan port which incorporates a waterproof o-ring seal and is held in place with four large stainless butterfly nuts on four standing bolts. The bottom of the multi-layered lexan port is aligned perfectly with the bottom of the boat. (we got lucky.)
http://ford.physics.fsu.edu/XenaDrive0430.jpg

To use the motor, remove the port and insert motor.
http://ford.physics.fsu.edu/Birdrack.jpg

To sail, remove motor and bolt port back in place.
http://ford.physics.fsu.edu/Xena078.jpg

This works well with the Caledonia Yawl because she is a real load carrier and doesn't much notice the extra weight of a 47 lb. 4 HP 4 stroke and its 3 gallons of remotely contained fuel. In fact she kind of needs the weight to settle her down. However with the Fulmar, I would think that kind of weight would cut into how much crew she could carry.

What I like about my set up is that the heavier than usual motor (for a Caledonia Yawl) can be wrestled in and out of place by two people standing in the middle of the boat. I especially enjoy steering with the rudder under power because I am well removed from the noise and vibration of the motor. Because the motor is a bit over-sized for the boat, it can run contently pushing the boat at hull speed at 1/2 to 5/8 throttle and there is plenty of reserve power available for any occasion (need a tow?). And of course with the remote tank, you can run all day without refueling. Under power, standing in the stern with the tiller of the rudder in my hand, she feels like a very well-behaved motor launch. I then still have one hand free to wave to curious passers-by (or to yank the kill switch from the motor). The other thing is that with the port in place, there is near zero effect on the sailing performance, at least with a Caledonia Yawl. I still say that the little 2 HP Honda is a better choice for the Fulmar. The Fulmar was designed to plane under sail and I suspect that the heavier motor and larger fuel capacity would hurt the Fulmar's designed purpose in life.

[johnw]

Beware! Beware! His flashing eyes, his floating hair
Close your eyes with holy dread
and weave a circle 'round him thrice
for he on honey dew hath fed
and drunk the milk of paradise.


With apologies to Coleridge, Kenjamin has forced my hand. Now I must talk about wells.

It's not so easy to seal a motor well so that you don't have a lot of induced drag. Not only that, but even if you do, you've got what? A big damn hole in the boat. Forget to seal it up and what happens? The boat heels, the water starts coming in, and the free surface effect of the water in the boat destroys the boat's stability.

Plus the motor is inside the cockpit. Which means the exhaust from the motor is inside the cockpit. This is not the very best thing for the crew, but it's also not the best thing for the engine. Stinky Johnson, the outboard I had in the well on my Yankee One Design, could not only sicken the crew, but breathing his own exhaust would sicken him. Especially on a long leg downwind, Stinky would be breathing his own effluent, and would run down and eventually stall.

Fanning him with a piece of sandpaper or cardboard helped. But I was keeping the boat at the Center for Wooden Boats, and I couldn't always control the people taking her out. Sometimes people would be sailing the boat and would fail to take the engine out and seal the well. I had nightmares about the boat sinking because someone forget to seal the hole in the boat.

Plus, when I went sailing, I usually didn't use the engine -- never have trusted the damned things -- but if I did, I needed a designated Big Galoot to take the engine out of the well and put it in the cabin.

On the whole, I prefer no engine. If I must have an engine, I prefer no well.

[keyhavenpotterer]

In Iain O's own words " Fulmar can make an excellent launch with either inboard or outboard power"

http://jordanboats.co.uk/JB/IainO_Catalogue/Fulmar.pdf

On the smaller Shearwater he says " the hull shape is ideal for outboard power as the hull planes well.
http://jordanboats.co.uk/JB/IainO_Catalogue/Shearwater.pdf

Brian

[rbgarr]

I can shed some light on the E power numbers: Assuming 16' lwl; 800 # for boat and crew; 250# for (4) 105 ah 12v batteries and 50# for motor, controller, charger, etc you could go 5 mph for 16 miles. The electric bits would cost about $3000.

This Torqeedo unit (at a similar $3K) might be something to consider in an application like the one described here that aims for quiet power and light weight.

http://i40.tinypic.com/20zp7wm.jpg

The review claims the equivalent of 6 hp (I'd need to be convinced) and has remote plug-in controls allowing for removal and storage off the transom or rudder. I also wonder if it's the kind of unit that could be installed like a Saildrive in a heavier displacement boat. The battery requirements (proprietary) are unclear to me however:

http://www.boatbuilding.net/article.pl?sid=08/07/07/1138229&mode=thread

[kenjamin]

johnw,

Maybe because it's a small brand new 4 stroke, or maybe because it's in an offset well so I'm not in it's vapor wake, or maybe because I stand a lot when motoring, or maybe because most of the time it's running at half throttle, or maybe because it's home is a very large well but I haven't noticed any fumes while cruising (starting up yes – moving no) and it runs so smooth that it's more like a sewing machine than an outboard motor.

I think it's time you parted ways with your stinky Johnson and got yourself a yummy Yamaha.:D

[Chris Ostlind]

The Yamaha four strokes exhaust underwater through the prop when in gear. When in neutral the exhaust is above the waterline. Keeping onboard fumes to a minimum would mean limited running in neutral and that is about all there is to it.

For small engines, you really will be pressed to find a better engine than a water cooled four stroke, They are quiet, powerful, tend to sip gas in the low to mid rpm ranges and last a very long time.

If Evinrude extended their E-tec line down into the small engine range, they'd get a lot of customers back from the Nissan (Tohatsu), Yamaha and Honda owners.

Chris O

[Kaa]

The battery requirements (proprietary) are unclear to me however

Battery requirements are easy to figure out. The energy density of lead-acid batteries is well-known, so all you need to do is to decide how much power you want to spend for how long, assume some reasonable number for the engine's efficiency, and then see how many batteries of what size will you need.

Kaa

[johnw]

johnw,

Maybe because it's a small brand new 4 stroke, or maybe because it's in an offset well so I'm not in it's vapor wake, or maybe because I stand a lot when motoring, or maybe because most of the time it's running at half throttle, or maybe because it's home is a very large well but I haven't noticed any fumes while cruising (starting up yes – moving no) and it runs so smooth that it's more like a sewing machine than an outboard motor.

I think it's time you parted ways with your stinky Johnson and got yourself a yummy Yamaha.:D

Stinky was a 1965 2-stroke, 25-1 mix. I showed him the door when I sold the Yankee, and the new owner got a Yamaha. Stinky now lives on a Thunderbird with a well that is separated from the cockpit.

Sending the exhaust out with the slipstream is a very intelligent solution. Still not wild about having a hole in the boat, though.

[Lone Star]

This has been a very good "thinking chair" excersize for me, as life (kitchen remodeling in this case) has once more interrupted my boatbuilding. It is going on five years since I started the build.


I've got you beat. This will make year 7 on my Fulmar build.

[djtil]

I've got you beat. This will make year 7 on my Fulmar build.

Well, that's what you get for taking the time to clean your shop.

Is there another installment for Watercraft in the works?

[Lone Star]

Well, that's what you get for taking the time to clean your shop.

Is there another installment for Watercraft in the works?

Nothing in the short term. Hopefully I'll have enough material to be able to submit an article later in the year.

[kenjamin]

...
Sending the exhaust out with the slipstream is a very intelligent solution. Still not wild about having a hole in the boat, though.

johnw,

The hole in my boat doesn't matter too much because I routinely carry about 500 lbs. worth of flotation on my fishing adventures – eleven 6 gallon heavy duty water jugs. With the port removed the live well / motor well doesn't fill more than six inches or so. With the port's waterproof seal working and bolted in place, the entire motor can be stored in the well or if I need ballast for sailing, it can be filled up with water. If the boat should get an unexpected hole somewhere else, the flotation will keep two of us and the motor above sea level. At least that is the plan. I really hate swimming with the sharks – so far so good.

[bheys]

We have the 2hp Honda motor for our Fulmar. It is more than enough power for the boat although it will not come up on a plane. I thought it might be limited by the small gas tank, but it sips fuel; we rarely find the need to run above half throttle. Frankly, it is always somewhat of a relief to be able to shut it off and tilt it up. Of late, we rarely bring it along, haven't used it in over a year. It is only 28 lbs, but it makes a difference hanging that weight off the transom. When the Fulmar was new I managed to embarrass myself at a launch site while trying to motor away. No steerage, almost did a 360. Dropping the centerboard a tad and all was fixed.
I wouldn't accept opinions that the Fulmar is ill-suited to beach camping/cruising (for that purpose there may be better boats however). There's lots of room, the sail area can be managed to the conditions, she is dry enough and you'll get to your destination quickly.

[djtil]

Bruce,

Thanks for your insights about Fulmar. I'm glad you still are enjoying yours. If mine comes out anywhere as nice as yours, I will be happy.