I recently bought a caper cat
http://www.calypsosailcraft.com.au/boatingsails.htm

an interesting 14 ft cat produced locally in brisbane australia. Its
capable of carrying 6 adults thanks to extra flotation in the hulls and
seems fairly robust. Jesse Martin (of youngest solo round the world
fame) sailed this cat from brisbane to cape york with his brother and
father as a younger squid. weighing in at 245lbs with 143 sq ft of
sail area and a mere 9 inches of draft this is a pretty quick boat to
me. There is quite a lot of storage space in the hulls so that 2
adults could realistically go coast cruising/island hopping for a week
or 2 at a time without re-provisioning.

This boat has an outboard bracket factory fitted. It looks a bit
flimsy but is rated for 5hp. I work as an engineer in a shop with very
comprehensive tooling (benders, mills, presses, MIG and TIG aluminium
and stainless steel) so beefing it up a bit poses no significant
problems. This boat will be used exclusively in salt water and i
picture the outboard having 2 useswhich probably oppose each other; as
a 'get out of jail free card' it will help me out in any situation when
im in the brown and smelly... getting too close to rocks, fighting a
tidal current, trying to get over a sand bar with heavy waves etc or
any other situation when wind alone just wont cut the mustard. The
other situation is mid distance cruising; picture yourself 5 or 100
miles off the coat and desperate for beer, pizza, water, medical aid or
whatever ails you. There is no wind. The motor is your salvation.

I'm hoping to carry less than 4 gallons of fuel at any one time so i
guess what im asking is this; how many hp will give me the ultimate
bang with the best mileage? I've seen engines rating from 2hp 4
strokes to 20hp 2 strokes of varying ages and all within my budget, but
what is going to do it for me? ultimately economy is probably the main
concern, but i need enough power to get me out of tight spots if need
be. The motor will be mounted permanently and used every day, so
maintenance will be of some concern, but it only has to last a year
after which time i would be happy to dedicate it as an anchor. FWIW
the previous owner said he had a 5 on it and it was mufch more than
what was needed... whats the right way to go?
Shaun
Australia