Jury Rig Catamaran Propulsion

[geoleo]

Originally Posted by MVLillyBelle

My son has recently acquired a 12-meter cruising cat in Norfolk, VA which he needs to move to the Vero Beach, FL area in the next month or so. She currently has two inoperative diesel saildrives (27hp Yanmars, I believe) which he would prefer to deal with after he gets to FL. Our plan is to lash an 11' RIB with a 20hp 4-stroke to the bases of the davits on the aft bridgedeck, triangulated with lines from the RIB's transom to the cat's transoms for lateral rigidity while still allowing some vertical flex to keep the outboard in the water in waves. This is intended to be used primarily for maneuvering out of the marina and negotiating bridges, etc. We hope to be able to sail most of the way in open water. Questions: (1) Does anyone here have any experience with such a rig? (2) Does anyone have a better suggestion? (other than the obvious "repair/replace the saildrives") (3) Given the vagaries of weather and the fact that it is hurricane season, should we go outside in hopes of getting favorable winds for sailing, with it's incumbent dangers, or should we take the longer and probably slower inside route with its potential bridge delays, etc. and very limited sailing opportunities? The mast is 55' (cutter-rigged) and the draft is 4'. All opinions are appreciated.

SO your going to be dragging the dinghy in the water while trying to sail? lol Motoring on the ICW will take about a month Norfolk to Vero. Offshore about 6 days. Why don't you replace one engine? Best is to fix it where you are the cost diff will be negated by the struggle to dingy it to Vero--what is this boat??

[geoleo]

30HP YANMARS WITH SAILDRIVE packae complete. available from Mastry in St Pete for $7812 if you tell them your in Marine fixit biz......Send the old ones to that guy in Wisconsin for a rebuild credit

[MVLillyBelle]

The boat is a 12-meter Sunstream, circa 1990. While the ultimate destination is Vero Beach, FL, our intermediate objective is a boat yard/marina in Hampstead, NC just above Wilmington (mm 267, if memory serves). If the rig is just too ungainly we plan to haul her there and make whatever repairs deemed necessary to continue safely to FL.

Thanks for the tip on the sail drive...will definitely keep that in mind!

[Goodwolf]

Or you could just sell the cat to someone that will repair her where she is now?That way you could protect your investment, and the boat from an unsure future.
If that interests you, call or email me if you'd like a better option than what your looking at now.

[ozskipper]

Just mount an outboard bracket to the transom and do it properly. They are cheap and it can stay there as emergency propulsion for the future.

[Atlantic42]

We've run large sections of the ICW with a outboard powered PDQ36 catamaran, usually running just one engine to save fuel. So conceptually, the ICW route works with a transom mounted outboard.

However, if the 20hp dinghy engine has a short or standard shaft then I'd be very concerned with swamping the engine if it's transom mounted to the cat. Big powerboat barging past laying out a HUGE wakes!

Seems to me the engine of choice would be a extra long shaft high thrust 4 stroke 9.9hp Yamaha. Good grunt at low speeds, fuel efficient, reliable, readily available second hand (check the PDQ forum for a used one or two) and the extra long shaft should keep both the prop in the water and powerhead from ingesting water.

Thoughtful attention to mounting the motor securely and the addition of standard throttle and shift controls and all you need is a little luck to get to NC. Some small outboards even have a 12V battery charging circuit albeit it will be modest modest at 8 amps or less.

Starting, stopping and slow speed manoeuvring will present significant challenges with just one engine when mounted far off center. When starting out it's likely the boat will turn 60 or more degrees before making useful forward movement and only then begin responding to the helm. Dealing with the bridges will be a pain.

Wishing you good luck with your delivery