When two boats share the same hull type — in this case both the Nautica RIB 20 Catamaran 2011 and the Nautica RIB RR40 Rescue Boat 2011 are inflatable rigid designs with fiberglass construction — the buying decision usually comes down to a handful of practical questions: how many people are you putting on the water, how far do you trailer, and what does your tow vehicle weigh?

The power gap is worth calling out. Rated to 115 hp, the Nautica RIB 20 Catamaran 2011 has a 75-hp advantage over the Nautica RIB RR40 Rescue Boat 2011's 40-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load.

For family outings this is probably the sharpest distinction between the two. The Nautica RIB 20 Catamaran 2011 is rated for 16 passengers, while the Nautica RIB RR40 Rescue Boat 2011 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Nautica RIB 20 Catamaran 2011 could be the deciding factor.