Originally Posted by Polwart
Stephen, I don't think you could damage one of these by accident - you would need to really try. I hit a concrete jetty at a fair speed recently (LEARNING POINT - when refitting throttle / gear cables check they are set properly to neutral and tick over - before starting the engine). It scratched the surface only - had it been fibreglass it would have needed serious professional repair. Of course a "true" rib would probably have bounced (or burst!).
The 570 (and the smaller Mac Attack) both look like RIBS. I have seen them in the flesh. I have a FunYak 3.90 Sparfel. I think it looks pretty rib-like. There is a bigger 5-6m ish one which also looks riblike (although a little square fronted for my taste), and has a-frame options etc.
Repairing them if you manage to damage them is not impossible:
scratches - sand out with wet and dry and heat gun restores the finish.
splits - can in theory be welded (not with a standard welder though!). I guess you could patch/fill if necessary too.
I have to confess that whilst I am a big fan when the time comes to upgrade I will be considering hypalon ribs too.
I just like the idea of something that isn't easily damaged because what would be an "oops" or "bugger" in the UK is a major hassle here as has been proved for the last six months because there just isn't professional expertise available. Hypalon seems to be damned fussy stuff to repair and I don't have the facility or the expertise to do it 100% as new. Having watched the video clips on the Mac boats being dropped from cranes, run up on beaches, dumped off trailers onto slipways etc etc they seem fairly bombproof which is good, most of those things would have wrecked a RIB completely or at least caused expensive damage!
Temperatures here are not extreme cold contrary to popular opinion and the media, most winters days are a few degrees above freezing, much like the north of England if a little colder than the South.
There's also the issue of tubes when at moorings - it would be partly solved by having blowoff valves so you could leave them really hard. The mooring I use, while it is sheltered by our standards, can see 2ft waves on occasions when we have NE winds and I've watched my boat with 25-30kt NE'ly, when the tube is soft on a cold morning it will really wrench and heave on the tubes where the cleat is bonded on with probable long term damage potential - a solid "tube" or an aluminium hull would remove that problem.
My basic conclusion is that RIBs are great if you have somewhere sheltered to put it and an expert to repair it but sadly in these parts I don't have either
Thanks for the comments everybody
at the moment I think Mac is in the lead....