Multihull Types of Drives

[rowdog]

hello all / any

new guy on the block looking to get some insight / advice ...

have been working towards the goal of purchasing a 1st boat and will claim 95% sure i would go with a used catamaran,
could swing the 100 - 175 K range
my intentions are sailing anywhere / everywhere
engines are turned on only when absolutely necessary...

tho i get most of my general practice time on a catalina 350,
i've been fortunate to help on a few deliveries ,
tho mostly motoring
on a few cats; leopard 40, 39 and a lagoon 43 ...
i find those sat very high and wonder what other makes might be a bit more streamlined like the PDQ's i have seen,
but newer ...
speed is less the concern then stability for me ...
tho i welcome all debates ...

so:
* power / propulsion..
what's the consensus regarding sail drive VS shaft drive
* dagger boards VS centerboard
* are small outboards feasible
* size as it likely would be single handing predominantly

thanx

[Cotemar]

Most power catamarans have Shaft drives.

Most Sailing Catamarans have Sail Drives.

Diesel engines will be more fuel efficient and easier to maintain, but cost more.

Always go for engines that are one level up from the standard ones.

A few boats use the Yami 9.9 high thrust engines. These are way under powered for most any catamaran.

If you do choose the Yami 9.9 high thrust engines. Make sure they are mounted mid ship.

Stern mount engines on a catamaran sucks exponentially.

[valhalla360]

Generally above 35', you are looking at shaft drives or saildrives.
- Having owned a shaft drive power boat in the past I hate the constantly wet bilge but not overly crazy about a permanently submerged sail drive.

Under 35' outboards or outdrives become an option. Both have the advantage that they can be completely pulled out of the water limiting drag while sailing and corrosion issues from being constantly in the water.
- The Stillete outdrive is the most common if you are dead set on diesel but with the new 4stroke outboards the fuel efficency edge is drastically smaller. While mechanically simple, the stillete requires regular maintenance if you hope for it to be reliable.
- We have a 25hp outboard in a lowering bucket. Works nice, almost as good on fuel efficency and maintenance is negligible. Worst case a few grand and we have an entirely new drivetrain in an afternoon.

[rowdog]

thanx for the info ,,,

as i am new , i admit to expecting a few more responses
as well as more in depth views , in particular with regard to dagger boards

i will say that individuals i have been able to ask, in the area, do think a shaft drive is a better choice..tho i am finding a lean towards some of the outboards i come across in various searches ...and , as mentioned being able to get em out of the way ...

more then likely, i am being a bit naive , but my only real lengthy trip ; a month in the bahamas may /1985
...st george >>>> turks-N-caicos ...
my buddy who owned the boat, 37' ketch ,
never turned on the engine...

anyone , any thoughts on dagger boards being put in place , after market on a 37' lagoon..... 20 yrs old ?

thanx again

[atoll]

cant beat a shaft drive with a folding prop for reliability.

sail drives work well BUT they create drag ,you are unable to change oil seals in the water,risk serious damage if they hit something or snag a ground line,plus potential leaks from the diaphram.

outboards can cavitate,and not really fuel efficient,for long motoring passages.

[clockwork orange]

When I first bought my Gemini 3000, before I had actually motored it I had convinced myself that I would need either 2 outboards or a single 15 or 25hp outboard, i was wrong. After a 1500 mile delivery home under power i am totally satisfied with the single Yamaha 9.9hp high thrust on the central bucket that steers with the rudder. We were able to cruise at 6+ knots at about 7mpg with absolute reliability. It was enough(just) to make way directly against a 25k headwind and seas to match, i don't believe more hp but less thrust would have been an improvement. I love those motors.

Steve.