We have a 3.5m (11.5 ft) RIB
on ours with outboard engine
attached, and it fits like it was the basis of design. The weight of RIB
together is not more than 110 kg (240 lb). A 4.0m RIB with outboart attached might fit, but I would think that it would be getting pretty close to the limit of the clear space between the hulls.
I don't have access to the Leopard
Owners' Manual at the moment, but I don't recall
that it gives a maximum weight, probably because it depends on the worst sea conditions that are experienced. We've had ours on the davits in up to 6m (20 ft) waves and the davits showed no distress
afterward. In smooth inland water
, you could probably carry a good bit more.
I have generally found The Moorings in Florida
to be more responsive to such questions than the factory itself.