big jet drive
 

I know this may be a dumb question, but why dont they put jet drives in larger boats like 30+ footers if the drives are cheaper?

Re: big jet drive
 

Because they suck!!! They may be cheeper but they are very inefecient they use 25% of the engines power to run themselves where a sterndirve will use more like 4-5%. They also have very poor docking manners and tuneing them precisley Enough to run on a twin aplication would be a nightmare.

Re: big jet drive
 

:D They both suck and blow! :D

I have seen a few in twin applications. The idea is very appealing if you have shallow water or sandbars where you boat, but they simply are not as eficient.
I would think slow speed handling would be better with twins than with a single.

Re: big jet drive
 

they have 30 foot river boats that carry about 30 people,with 3 jet drive's on them.the acceleration is awsome.I think there is a speed limit on how fast a jet will travel,unlike a prop

Re: big jet drive
 

They are actually efficient within their operating range on a boat designed around them. There are a good number of huge fast mega yachts running them. They are power eaters at low speeds.

Benefits - shallow draft.
ability to throw into reverse at speed (brakes)
ability to handle monster hp (without adding to draft).

Did you know that many of the more modern large tugboats use a waterjet on a 360 degree rotating swivel nozzle?

If they weren't efficient, I assure you that the commercial trade would not use them.

But why none on a 30 foot perf boat?
Cause there's no market for them.

People wold rather buy a fragile Merc Bravo because they are familiar with it...