Bow Rise, by Design?

If you set my boat on a flat surface, neither the bow nor the stern would touch the floor. Because of this the Bow rises a little more and the stern diggs in a little more than I would like.<br /><br />The motor is running good now. I had to raise it about two inches to get it in the right position. I've tried a Doel-Fin but not really any results.<br /><br />Anyone have any experience with these types of boats? Is this how it should be running?<br /><br />Thanks<br /><br />pictures:<br /> http://www.kalebtrahan.com/pirogues/bigmamma.htm

Re: Bow Rise, by Design?

Sorry:<br /> http://www.kalebtrahan.com/pirogue/bigmamma.htm

Re: Bow Rise, by Design?

Looked at your fotos, That's some helper ya got there. <br />Looking at image 93 I think, is the stern view. It looks to me like that engine could come up another 4". I'd want the dolefin at least even with the bottom and maybe higher. Raise the engine up until the dolefin is even with the bottom and then raise it 1/4" at a time with strips of 1/4" plywood between the clamp and top of the transom. When it starts to cavitate, drop it down 1/4". The more engine out of the water, the faster it runs. The faster it runs, the more boat comes out of the water.<br />Keep posting so we know how you're doin' and take care of your helper.<br /><br />g'luck & c/6<br /><br />Hooty

Re: Bow Rise, by Design?

I agree, bring the motor higher to align the fin as previously stated.<br />Over here that would be called a dory. The flat bottom and garish rake to the bow set it apart from other boats.<br />Treat the first 8 feet from the stern as if thats the whole length of the boat and then see how it behaves. You'll find a lot of the bow section out of the water and looking high when under serious power, but it all settles down when idling.<br />Please keep us up to date with developments.<br />Ross

Re: Bow Rise, by Design?

I agree the motor needs to be raised and adjusted a little at a time to best performance.<br /> I think you have a semi displacement hull and<br />your motor is much more than the hull needs to run at its design speed.With the amount of rocker <br />it will run with the bow high.You can force it to go fast but it wont like it.<br /> My guess is it would run at its design speed<br />with a 3hp.That narrow stern does not work well<br /> as a planing boat.<br />It appears to me it would row quite nicely for<br />its relatively short length and blunt bow.

Re: Bow Rise, by Design?

That's a picture before I raised the motor. The motor is now as high as it can go, while still being able to supply water to the water pump. The water inlet on the 9.5 is above the cavitation plate.<br /><br />Thanks

Re: Bow Rise, by Design?

That is not a displacement hull in any way or sort. It is meant to plane. The "rise" is called rocker and in this application probably helps the boat turn easier more than anything else. Rise at the stern makes the boat squat...which helps tracking while towing too. The boat is running as designed and the only common fix is to trim the engine THRUST down to push the bow down. Trim tabs are another option...you could install fixed plywood tabs, another common fix from the plywood skiff days of 50s & 60s.

Re: Bow Rise, by Design?

The key word is "semi displacement"<br /> It certainly is not a true planing hull.<br /> The whole hull is narrow and especially the stern is narrow.<br /> Sure you can get it up on the water but it will be more comfortable at 6 or 8 mph.<br /> Im betting the hull info reccomends less than 9.9 hp and designed hull speed is less than 10 mph.<br /> By the way Joey thats a very nice building<br /> job.<br /> Some nice slat floor boards in natural finish would be the finishing touch.

Re: Bow Rise, by Design?

Hull rocker also helps a boat row easier.<br />It helps keep the transom dry so it glides easier<br />and holds speed better between strokes,<br /> one of the features of a displacement hull.<br /> A narrow hull drives through the water easier<br /> another feature of a displacment hull.The transom narrower than the main part of the already<br />narrow hull another feature of a displacement hull<br /> so it is easier to drive "through"the water.<br /> There is an inboard boat on the current "Wooden Boat" magazine cover It has many design features of Joeys boat. It is designed to be driven "through" the water at 6 or 7 miles per hour<br />(displacement speed) <br /> And it gets something like 30 miles per gallon.<br /> Pretty much unheard of in boating circles.