Reply
 
Thread Tools Search this Thread
 
Old 14 October 2010, 16:09   #1
Member
 
Country: UK - Scotland
Town: Fort Augustus
Boat name: Ness Express
Make: Humber / Quinquari
Length: 10m +
Engine: Volvo D6
Join Date: Jul 2008
Posts: 17
Outdrive versus Jet, Which would you chose ?

Hi all, we are thinking about upgrading our fleet and wondering about the operating values of jet drives over our trusty bravo 2 legs.

Discuss !

Cheers
__________________

__________________
Ackee is offline   Reply With Quote
Old 14 October 2010, 16:27   #2
Member
 
Country: UK - England
Town: NW& wherever the boat is!
Boat name: depends on m'mood!
Make: Humbers/15-24m cats
Length: 6m +
Engine: etec130/big volvos
MMSI: many and various
Join Date: Nov 2001
Posts: 1,815
just love twin jets.........
__________________

__________________
Dave M
www.wavelengthtraining.co.uk
wavelength is offline   Reply With Quote
Old 14 October 2010, 18:36   #3
Member
 
Country: UK - Channel Islands
Town: Jersey
Boat name: Archangel
Make: Ribcraft
Length: 6m +
Engine: ETec 225
MMSI: 235063789
Join Date: Sep 2008
Posts: 1,005
Advantages of jet drives are that they offer increased manouverablity (see this video: ), they can operate in significantly shallower water and there's nothing to hit below the waterline like a prop or a leg.

The downside is they are less efficient than a conventional sterndrive (by about 30%) and so require a larger engine to maintain the same horsepower. They are noisier and vibrate more as everything's inside the boat (they also take up more room as a consequence) and they are more expensive to buy and fit. Also, if you're not careful you'll suck up stones or weed and this will damage the impellor and may stop the boat in its tracks.

Mind you, how many stern-driven ribs would dare try this? - (f/forward to 1:35).
__________________
GJ0KYZ is offline   Reply With Quote
Old 15 October 2010, 07:31   #4
Member
 
Country: UK - England
Town: Various
Length: 6m +
Join Date: Jun 2009
Posts: 30
Personally I have only driven military jet drive ribs which I found to be brilliant on flattish water but as soon as the swell picks up lacks drive when you leave the water due to the propulsion system needing to intake water to constantly drive the boat forward. I found them not to be that great either when operating in aerated/turbulent water ie surf or coming alongside a ship underway not ideal to be losing drive whilst trying to embark a boarding party but hardly a problem youd find with a commercial operator.
__________________
colblinky is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 11:33.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.