passenger catamaran

which propulsion system will be the best for a passenger catamaran service speed of around30 knot

 

That would depend upon the size of the catamaran. Outboards are probably the best. If an engine is acting up you can replace it easily with a spare while the troublesome engine is in the repair shop. That way you don't lose business in the meantime.

 

It is A good idea to have a spare engine! I've never seen. But of course, this great advantage is only possible with outboard motors. It's a little expensive but! Worth it!
There are other services, important for passenger vessels, which can not be powered by outboard engines. But maybe that's not worth being taken into account.

 

passenger catamaran implies a ferry, which requires commercially rated propulsion system and therefore not outboards.

Most passenger ferries use waterjets for a variety of reasons. However fixed pitch propellers on inclined shafts and CCP such as Servogear are also popular.

If you want the best fuel consumption at the cost of higher purchase price go for Servogear. If you want a low cost solution go fixed pitch propeller. If you want a good all round solution which is reliable, reasonably priced, easy manuevering then go for waterjets.

 

That law may vary from one state to the next. Very little detail was given by the OP as to size or type of boat other than that it was a catamaran.

Will it carry passengers only or will it also carry vehicles, and how big is it?

 

A "passenger catamaran", so far, means a catamaran for passengers. But if, in addition, carries vehicles, ie, it is a ro-ro ship, fortiori outboard engines are totally inappropriate. Unless addition to the outboard, the vessel has diesel generators.
And it is not a law that varies from state to state, but to feed the ship's essential services, in the most appropriate and economical manner.

 

The passenger ferry between Caladesi Island and Honeymoon Island here in Florida runs on twin 150 hp outboards.

Look at 1:42 near the end of this video:

http://www.youtube.com/watch?v=KGguA_Acg-s

 

Yes sir, it's true what you say. But we both know that I have the right.
What would you recommend, then, sundipkumar?. A spare outboard?. How many spare outboards reserve have the ferry between Caladesi Island and Honeymoon Island? Do her have one for each engine installed or just one for both?. Get us out of doubt, please.

 

TANSL, I don't work for the ferry company but I would be surprised if they didn't have at least one spare ready to go at all times. They run the ferry seven days a week and do plenty of business. It would be less expensive to rotate the outboards than to have down time for the boat itself.

http://www.caladesiferry.org/trips.htm

 

hoytedow,you know the number of ships in the world that have no spare engine?. (No, I do not know either).They all lose money when they do not sail. Do you really think the only solution, or the cheapest, is to have a spare engine?.
You should not defend your position by an affirmation of something you do not know, but suppose it's like you're interested it.
Let us, please, this discussion that leads nowhere. Our friend sundipkumar will undoubtedly amazed at the number of solutions that we are giving him.
Sundipkumar accept, please, my apologies, I end here this useless discussion. Think about not less than 10 times before putting outboards.

 

good grief but this TANSL chap is rather a nervous type, please dont bite mu head of for posting jeeez

 

I didn't know we were having an argument. I would be surprised if such a busy enterprise had no spare, however.
Peace.