2 speed trans in boat

[Keith2230]

The physics of airplanes is much closer to boats than cars. Don't know of any multi speed gear boxes on airplanes either (but they certainly could exist). Some can change the pitch of the propeller. This allows for more torque for takeoff and landing. Good because the stall speed is lower and it actively brakes the aircraft on landing. Then adjust to less pitch for cruising speed and better fuel efficiency.

I don't see why this wouldn't work on boats too but I don't want that kind of complexity or moving parts on my boat prop. Interesting topic but single speed with the correct engine and prop is as complicated as I want it on my boat and it works reasonably well.

[stevenbratt]

The physics of airplanes is much closer to boats than cars. Don't know of any multi speed gear boxes on airplanes either (but they certainly could exist). Some can change the pitch of the propeller. This allows for more torque for takeoff and landing. Good because the stall speed is lower and it actively brakes the aircraft on landing. Then adjust to less pitch for cruising speed and better fuel efficiency.

I don't see why this wouldn't work on boats too but I don't want that kind of complexity or moving parts on my boat prop. Interesting topic but single speed with the correct engine and prop is as complicated as I want it on my boat and it works reasonably well.

There are also other factors with controlling prop pitch to make sure the engine isn't destroyed.

Overall I think the system would be too complex and costly for anything other than a large cruiser.

[Stevext23]

There are several geared turbofans. https://en.wikipedia.org/wiki/Geared_turbofan

And, just like propeller driven planes, the pitch of those props actually rotates depending on the speed to manage the angle of attack requirements for efficient thrust.

[Z71_Silvy]

Think about it, 50 years ago 4 gears were plenty in a car. Now 6 isn't even enough.

50 years ago? I had a 4-speed in my 2006 Silverado.

But the 8-Speed in my Jeep is a gem. Power whenever I need it and great fuel economy.

[Mastar]

my bigger fear is running out of Fuel before I get back home....

Yep, ive done it too many times in my old boat. Hopefully the x-star gauge reads a little more accurate than my old malibu.

I like the idea of variable pitch props. Probably a little too complex for now.

Oh and my current 2007 silverado has 4 speed. Have to drop it in 4wd low to get up the boat ramp without bogging down