The original question doesn't have a single
answer. The following points are important:
- will it be used in the tropics? if so, hypalon material is a must. I would select that even outside the tropics.
- will you be mostly at anchor
or in the marina/harbor when both options are available? more at anchor
means more wish for RIB and big engine. It will be your car, you will spent more time driving the dinghy
than the big boat.
- is it windy where you will use it? if so, RIB + big engine + really big tube diameters become a need for dry rides. Cruisers without that tend to skip gatherings that involve an upwind trip through the choppy bay or bring a change of clothes. Nice for holiday sailing adventures, not for full time liveaboards!
- do you scuba
dive or snorkel? It'll become your dive-boat so again, RIB + engine. The further you go from the big boat, the more important safety
becomes. Do you dare to take it through 6-8' seas? You should...
- will you live aboard full time? rib is the only choice.
A RIB is always the right choice for all conditions for liveaboards. But you must have a garage!!! Davits mean a risk of loosing the dinghy
in heavy conditions but you might want to take that risk. We opted for an arch on the stern with a moving lifting arm so that the dinghy is high up against the pushpit. A spot on deck is another option, it would go either on the foredeck (cutter stay trouble) or under the boom (boomvang and/or sheet trouble).
The best dinghies I've seen are RIBs from Caribe and AB. Our Avon
RIB 310 was very nice until it developed cracks in the bottom (inner floor, no leak but always water
between the floors.) after taking it out into the big seas. I tried the aluminium bottom AB and like it for everything except single
person in choppy waters at high speed: too light and taking off too much. You really need to take dingies into plane for comfort and to be able to do distances.