Stephen, all down to budget !!
1) What make? I've seen Avon and Humber ones round here, I guess they are OK, any others to look for? any to avoid? Avon more of a "soft" type of rib, Humber is more offshore
2) Two smaller engines 35-40hp or one big one 65-70hp and a little auxiliary one for when it breaks? (which the 2 stroke ones I have seen seem to do quite a lot...) Four stroke would be nice but I think they are way outside a sensible price? i have allways gone for 1 large one with a small aux ! Four stroke have been left behind a little by the new gentation 2 stroke's, again down to budget
3) Looking at the Humber site, they do shallow-V hulls or deep-V hulls, which is best and why? From what I have read the deep hull ones are supposed to be better on rough water as they cut through waves rather than bouncing off but presumably the shallow ones require less water and therefore are easier to get on and off a trailer? The British Antarctic Survey apparently use the shallow V Humber ones which can't be a bad recommendation ... ? The deep Vee's need more power, but are better offshore/rought stuff, the med Vee's slam a lot more
5) What sort of age do they start to become a liability in terms of the tubes perishing? We have very strong UV here and there's no point in buying something that's half knackered already ... but I don't really think I want to go for a new one, a bit too expensive really. they recon on about 10 years,life for the tubes, but if a good make. & looked after, 15 years should not be a problem
as mentioned have a search and join Ribnet i have found very simalar to here !!
Regards Tim
Mine