I had a 12 1/2' Achilles inflatable with a 25HP outboard. With two divers, gear, cooler and a 12 gallon gas tank I could get to Catalina (22 miles), make two dives and be home in the early afternoon. I tried three divers once and it was too crowded and too heavy for the outboard. We made it 1/2 mile and turned around. I wouldn't try four divers in anything less than a 16 footer.
