Originally Posted by Silverfox
Why only 4m ribs?
RI/Hugo has run some events in the past for "4m" ribs. I don't think they have absolutely enforced a 4m rule, but its run for the benefit of small ribs (say 4.something m long). Many of those ribs are incredibly capable but don't cruise at the same speed as bigger boats, and may have an earlier "chicken out" threshold in terms of weather etc - so it makes sense to focus on a "size". Inevitably there are fewer people on board to share the nav and helming and bumpier rides which means the skippers need to think more about fatigue. The challenge of doing it in a small boat is completely different to the same journey in a "grown up" rib.
A 6m Osprey should be big enough that with good planning and training you could comfortably organise your own "around Ireland" trip or your own or with another boat. For very small ribs that possibility also exists, but most small rib owners would feel more comfort in a bigger group. Logistic support for refuelling is also completely different for a small engine and large one.