Filling the hole- or at least smoothing the flow.

[Mudisox]

Having obtained a smaller boat, [Hunter Duette], with the propulsion being outboard in a hole at the rear of the cockpit. It can be raised/removed but leaves an odd shaped hole which can't do much for the flow of water just ahead of the rudder blade.
Also when lowered there are "gaps' around the leg of the outboard, which again don't do much in streamlining.
Any suggestions as to how to improve the situation?

 

[Refueler]

You could create a fashion plate to drop into place to close the outboard hole - but would likely mean fully removing the outboard to be effective. I have a feeling that they originally may have had such a 'plate' ... I know some other outboard well boats had ..

As regards around the outboard leg .. if you close off - then how is cooling water going to 'escape' .. also I would not be inclined to have anything up against the leg as its alloy and would soon be scarred or worn.

 

[B27]

There should be a moulding which fills the hole when the outboard is lifted clear?
At least Impalas had them?

 

[wallacebob]

Have a look (join) Hunter Assoc: discussed a few times. A lot of the inserts are lost. I think they were bespoke, using the cut out hull section, so not off the shelf. Make one from grp formed on hull, with small dinghy bailer insert. Yet to do mine, only effects SB tack!

 

[PCUK]

I doubt streamlining would make any measurable difference to boat speed at your displacement speed. If it's not giving any problems might be better to leave well alone. I am sure you can find many other jobs to keep you busy.

 

[Refueler]

I doubt streamlining would make any measurable difference to boat speed at your displacement speed. If it's not giving any problems might be better to leave well alone. I am sure you can find many other jobs to keep you busy.

It was my thought as well .... The Duette is not exactly a fast sail boat .. no disrespect to OP / owners.

I cut a well into aft end of cockpit of my Snap 23 ... it made no difference to the boats general performance ... but the manoeuvrability was amazing ! Next owner - I always kept the hull piece I cut out - had the piece rebonded back into place ... I heard he fitted inboard engine ... the shaft tube and mounts were still there from its Vire 6 days ..

 

[MisterBaxter]

I think it would be well worth making a blanking plate, either from ply or somehow moulded in grp. Outboard wells can create a great deal of drag and turbulence, and you lose one of the joys of outboard propulsion, which is to get the prop out of the water and leave a smooth, clean run.
People also do things with neoprene flaps to fair around the outboard leg when it's in place, probably also worth doing.

 

[Snowgoose-1]

I've had a few boats with an outboard well where I have the motor permanently fixed.

I use these cut to size, and squashed in from above. Splash Swimming Kick Board
I mark in the well so that they are flush with the bottom. No water sloshing noise and possibly more hydro effecient.

 

[Refueler]

I know the Duette will not likely allow this ... but the well I cut on the Snap 23 - I could turn the outboard and it became a Stern Thruster ... I could slot that boat into spaces that others could never believe ...

 

[William_H]

One boat we had at our club I think it was called a "Marauder" had an o/b well right at the back including an opening in the transom. ie the mount for the motor clamps were about 50cms ahead of the transom. This meant that the o/b could be tilted up when sailing. It also meant the hole for the o/b did not have a stern edge so much less turbulence. The front of the hole was equal to the transom in terms of drag. However it did then necessitate twin transom mounted rudders. (Or a rudder mounted well forward of transom. I thought it was a good design though motor was not so far forward but far enough. Just waffling. ol'will

 

[john_morris_uk]

I made a blanking plug for the outboard well of our daughter’s Pandora. Not so much for speed and efficiency but more to eliminate the loud sloshing noises from the well. The one I made fitted round the outboard leg.

I laminated several layers of marine ply together and shaped them to fit the hole and follow the curvature of the hull. The whole thing was then coated with epoxy and glass matting and painted.

Main problem is holding it in place as it wanted to ‘float’ up out of position. Initially I fixed it with wedges hammered in but they work loose. I’m still working on a better fixing solution. .

 

[ProDave]

Similar boat here, Horizon 23 derived from the Duette. Our OB is offset in a well port side. It originally came with a blanking plug, and the original setup with a 4hp 2 stroke short shaft you could lift the motor and insert the plug.

It now has an 8hp 4 stroke long shaft that won't lift and the plug has long been lost by a previous owner, so the OB remains down. It is not particularly noisy but must lose us some speed.