jet drives?

[z1ppy]

Anyone with experience of them?

i thought they were pretty inefficient ?

Needed high engine revs (so perhaps noisy?)

application would be 30 ft ish picnic boat.

 

[Robg71]

Great fun, bury the nose when you drop the buckets at full chat. Turn on a sixpence,
Takes a while to get used to them....
Park your boat sideways with no thrusters...
Can't be that inefficient, plenty of commercial vessels use them.

 

[Greg2]

They are completely different to shafts and drives in terms of handling, particularly at close quarters but not too hard to master and once you have the boat will do what you want it to, including moving sideways.

I learned the hard way on acceptance trials with Redbay Boats in the harbour on Rathtlin Island. We were going to do some close quarters manoeuvring and the wind took us. I responded instinctively and it all went horribly wrong. Half an hour later following some tuition and a bit of practice I was handling it like I had been doing it for years

There is a school of thought that says they may not be so good in a seaway if the intakes become exposed and suck in some air but we crossed the Irish Sea from Cushendall to Islay in some very lumpy conditions and they performed very well. I think it fair to say that Redbay were impressed with what they had built (most of theirs are on legs).

They are not as efficient as drives so a ballpark 30% increase in HP required and higher fuel consumption can be expected. The drive train is also expensive when compared to outdrives or shafts.

 

[johnwest]

We had a work boat with Hamilton Jet drives a few years ago. Interesting to drive !!!!! Set the engine revs for the task in hand and it's all done on the bucket. But do not go from full ahead to full astern with full revs on. It will stop quicker than an F1 car.

j