17 degree transom angle, where did it come from?

[Toni V]

Heh, I'll make my guess:

The world needs standards. As said before outboards need to push bow down in some cases. If there would be a boat with 35 degree angle, no motor could be installed easily there. and if there would be a motor suited for 35 degree angle, it would not suit for the rest of the boats.

The angle helps in other ways too. There might be a need to reverse in waves. Most planing boats swim quite deep in displacement speeds and when reversing some tend to suck the aft even deeper. Angle helps there, the aft doesn't swim so deep and the waves don't come inside the boat so easily.

[fmiles]

Or perhaps it was observed that NO gap between transom and leg on a true 90degree transom performed worse with outboards slightly elevated(on flats powerboats for example) than one with a sizeable gap as in 17deg transoms. Guess wash coming off the hull bottom rises up a bit over a short distance.

[ks8]

Although Jason most likely has his answer already... I'm enjoying this.

All responses appreciated. I'm beginning to think that perhaps crop circles have nothing to do with it...

ks

[stickystuff]

For a small canal boat you still need the angle. The engine has the angle built into the mount. You don't have to worry about poirpoising in a small rig unless you get crazy and overpower it.

[LIVEWIRE]

canal boat racing. anyone interested?
i'm game.

[jasonmcintosh]

Although Jason most likely has his answer already... I'm enjoying this.

All responses appreciated. I'm beginning to think that perhaps crop circles have nothing to do with it...

I'm enjoying the discussion too, and so far crop circles is my favorite theory...

jason

[ks8]

Canal boat racing...

hmmmm....



http://lancet.mit.edu/decavitator/

... but it doesn't have a 90 degree transom ...

sir sticky...

For a small canal boat you still need the angle. The engine has the angle built into the mount.

If that be true, and Jason wants to use an engine at times, then I see three choices.

1- some sort of mount which negates the built in angle on the motor.
2- small additions on the bottom of the hull that will function as legs when stored vertically in the garage (you could mount your fish finder on one with a swing up mount).
3- build a small angled base that stays in the garage which the angled transom will fit into to keep the hull vertical. The wheels could be on the transom as before. But you would have to lug this base around if you are going to store the boat anywhere other than in the garage, vertically.

Have fun deciding.

Sincerely,
ks

[jacquesmm]

The transom angle is an industry standard.
Outboards are manufactured with that angle and transoms must have the same angle.

[JerryF]

So the angled transom is for fast powerboats with a need to control porpoising? Well then, to paraphrase what I learned when I was in high school, here's the general rule.....

“The angle of dangle equals the need for speed”.

You don’t want your bow coming up at the wrong time do you? Control is what it is all about. Or maybe it’s crop circles after all.

[ks8]

So crop circles made by porpoises were used to come up with a now industry standard on manufactured outboards. But back to the original issue, for Jason's sake...

If your canal boat wil be displacement, and not planing, and mostly for rowing...

me personally, in light of all the new info, I'd make a base to fit it into in the garage and keep the 17 degrees for those times when I want to hang an engine on it. This may also help resale value, ie, keeping the transom to an industry standard.

ks