bigger the better but you will be stuck for room along side your 60hp i had a 4hp on my 6m rib not a get you home a get you out of trouble.rule is 1 hp/m
I had a 6hp aux motor on a sailboat, but it would not push enough against the outgoing tide in some areas of the waterways. I would have to wait for the tide to change.
I upgraded to a 20hp aux outboard and was able to go against the tides, but still slow, the tidal current was very fast.
I would say a 9-15hp, but consider is your goal to get back to the dock or just keep off the rocks without a tow?
Ideally 5hp would give you peace of mind. I've got a Mariner 4hp squeezed in next to my main engine on my Ribcraft 4.8m. I'm under no illusion it may not necessarily get me home if it's blowing a gale, but it gives you options.
I used a 3.3 tohatsu 2 stroke on my old 5.2m Zodiac, would push it along about 4knts so not ideal but light and not too bulky. I rigged up a mount for it behind one of the jockeys as there wasn't enough room on the transom. With ribs this size its always a compromise.
spy-sea-one
Sula
