Transom height - OB shaft length

[MurrayM]

Hi there,

The transom height of our Whaly 310 dinghy is 16.5 inches...will a short shaft OB with a 15 inch shaft length be too short? The dinghy will not need to get on plane, just haul us, our photo gear, and dogs to and from the boat.

Is it "better" to have a slightly shorter OB shaft length than too long?

Dinghy will be under powered with a 5hp, so getting on plane isn't really an issue.

Any downfalls to using a long (20 inch) OB with a 16.5 inch transom height?

Thanks.

 

[Tad Roberts]

The downside of "too long" a shaft is the extra drag and vulnerability. Long shaft is a hassle around a shallow-sloping beach. Which is why I just bought a new short shaft outboard. If you're really certain of not trying to go someplace quickly the short should be fine. With a short shaft put a block of wood on the outside of the transom to move the leg aft from the transom, it will help a bit.

 

[MurrayM]

The downside of "too long" a shaft is the extra drag and vulnerability. Long shaft is a hassle around a shallow-sloping beach. Which is why I just bought a new short shaft outboard. If you're really certain of not trying to go someplace quickly the short should be fine. With a short shaft put a block of wood on the outside of the transom to move the leg aft from the transom, it will help a bit.

Thanks a bunch, Tad...especially for the wood block tip to move the leg / propeller further away from the dinghy

 

[Al]

Hi there,

The transom height of our Whaly 310 dinghy is 16.5 inches...will a short shaft OB with a 15 inch shaft length be too short? The dinghy will not need to get on plane, just haul us, our photo gear, and dogs to and from the boat.

Is it "better" to have a slightly shorter OB shaft length than too long?

Dinghy will be under powered with a 5hp, so getting on plane isn't really an issue.

Any downfalls to using a long (20 inch) OB with a 16.5 inch transom height?


Hi Murray- What was the selling points on this dink? Sure looks skookum in construction. .Will the material in this boat, even advertised as almost indestructible or lead to believe so, be repairable? Just seems some of the plastics are so that simple fixes unlike patches on inflatables, are worrisome, particularly where an investment that the Whaly reflects ($5,000.00?)
We use to have the Sportyac as a shore boat but the inability to find fixes for the leaks from beach wear. (There are kits, yet reported success on repairs is nil.) had us going to a small inflatable and a 2.HP Honda. It is short shaft and still I think, protrudes below the flat bottom to the extent that we have to raise the engine as we approach the beach.
We would like to obtain a small hard bottom aluminum inflatable when one comes on the used boat market. Those we see in action seem to be the cat's meow. Stable, agile, and easy to haul up on the swim step or top side where some stow.
Cheers,
Al
Al

 

[MurrayM]

Hi Al,

Selling points for us were that it's tough, stable with all three of us + our camera gear + the dogs, and doesn't need to be coddled like an inflatable.

You know the tides in our area...we plan on scooting up creeks and rivers on high tides (once we get the outboard) so our dinghy needs to be gnarly enough to get hauled over the odd gravel bar or stony beach.

Biggest con so far is that the 310 (10 foot) model doesn't self drain. Have a link somewhere of a small bilge pump which operates when a tow rope tightens and loosens while traveling, which should help a bit. Also made it work on the Weaver hardware on the swim grid.

The place in Ontario where we ordered ours from has the 310 listed at $3,765 Canadian, so quite a bit lower than $5,000.

Whaly Boats | Ultra Marine Ltd.

There is no perfect dinghy, just the one with the least amount of compromises for you, your needs, and the size of your vessel.

 

[Al]

Hi Al,

Selling points for us were that it's tough, stable with all three of us + our camera gear + the dogs, and doesn't need to be coddled like an inflatable.

You know the tides in our area...we plan on scooting up creeks and rivers on high tides (once we get the outboard) so our dinghy needs to be gnarly enough to get hauled over the odd gravel bar or stony beach.

Biggest con so far is that the 310 (10 foot) model doesn't self drain. Have a link somewhere of a small bilge pump which operates when a tow rope tightens and loosens while traveling, which should help a bit. Also made it work on the Weaver hardware on the swim grid.

The place in Ontario where we ordered ours from has the 310 listed at $3,765 Canadian, so quite a bit lower than $5,000.

Whaly Boats | Ultra Marine Ltd.

There is no perfect dinghy, just the one with the least amount of compromises for you, your needs, and the size of your vessel.

Good deal Murray! That price is compatible of a new hard bottom inflatable
.For the same reason, we like to or rather the Mrs use to like to, sneak up the creeks at high water to see what was around the next bend. Bears!!! and when the bears were behind us and rose to see what was about, the Mrs. decided then and there that was all the bear sight seeing from a dink she wanted!!!
No doubt the load factor as you describe calls for a larger platform. So yes, good choice.
I guess I will suffer with towing our 14 foot Wine glass row boat or a 12 foot sears aluminum skiff a while longer. The inflatable we have is more the going to shore than exploring.
On the Sears we use either a 4 or 6 hp Evenrude, both short shaft. The 2 hp Honda is for the inflatable.
Let me know how this rig works out later in the year. Particularly to the holding up around the beaches.

Cheers,
Al

 

[MurrayM]

Here's some Whaly photo's;

 

[MurrayM]

Hey, we both posted at 9:55.

Will let you know how it holds up for sure. As you can see from the photo's above, we wanted to strap it to Badger's ass on the Weaver hardware for tight quarter marina maneuvering; that kept its length to less than 11 feet, which in turn meant it had to be beamy and stable to carry all of us and our gear. (That photo is an early one...much better setup now).

 

[Al]

Hey, we both posted at 9:55.

Will let you know how it holds up for sure. As you can see from the photo's above, we wanted to strap it to Badger's ass on the Weaver hardware for tight quarter marina maneuvering; that kept its length to less than 11 feet, which in turn meant it had to be beamy and stable to carry all of us and our gear. (That photo is an early one...much better setup now).

Right on! One of the important reasons we liked copying your OB mount on the swim step was the ability to retain the Weaver set up. We purchased the Weaver unit for our inflatable then hesitated as we do tow our skiffs on occasion. Having the inflatable on the step defects efficient towing set up so we man handle and stow the inflatable to the top of the canopy.
Yep, pictures show well.

Al

 

[MurrayM]

Right on! One of the important reasons we liked copying your OB mount on the swim step was the ability to retain the Weaver set up. We purchased the Weaver unit for our inflatable then hesitated as we do tow our skiffs on occasion. Having the inflatable on the step defects efficient towing set up so we man handle and stow the inflatable to the top of the canopy.
Yep, pictures show well.

Al

Congrats on your 1000th post

 

[stubones99]

for that bilge pump for Whaley, are you talking about this?

Drainman Bilge Pump

 

[MurrayM]

for that bilge pump for Whaley, are you talking about this?

Drainman Bilge Pump

Yup, that's the one. Not 100% effective all the time, but better than nothing.