B35 hull bubbles

[Joef]

Hey guys. Ive been searching for b35s and have visited two of them out of the water. The first had a very normal looking bottom and running gear arrangement. The second had torpedo shaped bubbles molded into the bottom. They were not bolted, they were molded right into the hull. I’ve heard these were needed to fit the 3208 engines - and that boat had pair that had been removed.

Do those bubbles have any sort of drawback? I’d guess there is a little extra drag . Do they create any other negative (or positive) handling issues?

[Carl]

My guess, if your chugging along with 3208's those blown out sections will be meaningless to the boats performance.

Put lighter, higher horse power plants in, I'd suspect the drag becomes more noticeable...
I'd also expect the faster the boat goes the more those humps start to play a roll in performance aside from the drag.

Kind of like going slow it takes a good deal of tab to see a small difference in boats behavior...but pick up the speed and a little tab makes a big difference.

[Tony Meola]

I believe those bubbles were on some of the earlier models to make room for the transmissions. Like Carl said has to have some impact at higher speeds.

[Joef]

makes perfect sense guys. thanks

[Craig Mac]

Pretty sure Rybovich started using bubbles before Bertram to fit some motor/transmission packages---if it was good enough for them.....

[Carl]

Pretty sure Rybovich started using bubbles before Bertram to fit some motor/transmission packages---if it was good enough for them.....

That one does not hold water for me...a customer wants to install larger power then boat was designed for. Designer does not want to compromise "his lines" so opts to blow out the hull bottom where no one will see (when boats in the water). Customer gets his power plant, designer gets to keep their lines...so what there is some additional drag, your still going faster.

[Joef]

anyone know of anyone who repoweedr a bubbled hull w higher hp engines? the boat I looked at had 260hp 3208s (they've been removed now). I don't know if any of those were shipped form Bertram w 300hp 3208s or if anyone repowered one w 375 3208s or cummins Bs. The Cummins B's would be the likely candidate to replace the old cats. But not sure what issues the bubbles would cause w the power of a 330 or 370 Cummins. I suspect not too much...