Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

rs2k

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I just bought an old 28' boat with twin 260 HP 350s connected to two OMC 800 stringers. It's a cabin cruiser and is on a trailer which I plan to use everytime I go to the lake until I feel the need to get a slip.

I'm used to a very heavy 18' trihull stringer which I have no problem controlling. I've also piloted a large and very ungainly pontoon boat, but I've never piloted a boat as large as this cabin cruiser before.

What do I need to know before I take it out onto the water? I believe the hull designs is considered a vee-hull with sponsons. It also has enough power to plane on a single engine.
 

MikDee

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

You're probably going to need to have hydraulic trim tabs, if you don't have them already. A boat like that might have trouble getting level on plane without them, and probably list to one side at times unless you have them.
 

rs2k

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

The boat has the OMC trim system where the entire engine moves up and down. Do you think that won't be enough?
 

rs2k

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

I enjoy turning hard at a decent clip with my little trihull once in a while. I assume that's a big no-no with a boat this size.
 

rs2k

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

When I turn the boat at low speed should I rotate the drives or should I change the direction of one of the props?
 

David Greer

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

your trim system only adjusts the hull bow to stern. Tabs will adjust it beam to beam.
 

rs2k

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

So I cannot adjust one engine up or down a little more to adjust for list?
 

tashasdaddy

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

no. and remember reverse is not a brake. takes a lot more to dock it, than the 18'
 

JoLin

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

When I turn the boat at low speed should I rotate the drives or should I change the direction of one of the props?

If you need to spin the boat around in tight quarters, yes. If simply turning, no. Use the tools at your disposal in the proper fashion.

-You use your steering wheel (not the motors) to steer the boat

-You run your motors in a synchronized fashion- same RPM, same trim angle. Otherwise, they're working against each other to some extent.

- You use your outdrive trim to adjust fore-aft attitude, i.e., bow high vs. bow low. You already know how this works in your current boat.

-You use power trim tabs to compensate for side to side "list". Use the boat for awhile and find out if that's really an issue for you before you spend the dough.

Approach every close quarters situation very, very slowly (crawl). That boat is real heavy- the momentum behind it is exponentially greater than it is in your 18.

Hope the boat's a good one. Have fun!
 

David Greer

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

That's a big jump. I grew up in boats under 19' when I had an opportunity to drive, solo, a 27' cc with big twins. The comparison was like a bicycle to a bulldozer. For one thing, you can't get "close enough" and then grab the pier, piling, whatever and pull yourself right. Current is a much bigger factor. You will use the throttles instead of the wheel at the docks. I got confused on the throttle steering at the pier and did a 360 to get out of the marina and into the channel!
 

This_lil_fishy

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

...and you all forgot..the second mortgage to cover the fuel bill.
 

rs2k

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

True... But it's also paid off. :D

Instead of a boat payment I get to pay quick-trip.
 

25thmustang

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

Twin engine manuvering is actually easier (in my opinion) than single, because at idle speeds you can use one engine in forward, one in reverse to make the boat do what you want. A twin engine boat can basically spin around in a circle slightly larger than the length of the boat. Also remember though, wind and current will play a larger role, as will the boats momentum. Take it out and practice in the open...

Also getting it on and off the trailer will be a good bit tougher than your 18'er.
 

rs2k

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

The stringer drive on the tri-hull allowed it to rotate within its own beam width. I'm anxious to see what this big boat can do maneuver wise.
 

180shabah

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

I suggest a copy of chapmen's. Great book that covers all things boating.

Also, it probably won't make a very good towboat for tubers and skiers, although we did used to tube behind a 28' Grady with twin Yammy's...
 

rs2k

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

I will of course try towing people behind it, but I do intend to keep my 18 footer for that purpose. The main reason for the 28 footer is trolling / fishing / camping / and ocean going as soon as it gets to cold for my local lake. I wanted a second engine for those far out sword fishing trips. The idea of being 20 miles out into the gulf stream at night with only one engine is not something I'm comfortable with. I've also been told that this make and model of boat handles large waves well.
 

BiggPops

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

I think thats great youre graduating to a larger boat. I have been boating on my own since 16 and am now in a 18.5' and have been looking at the larger mid to high 20's for the past two years. I just haven't reached down and grabbed the boys yet. I'll be in one soon enough though.
 

Andy in NY

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Re: Going from an 18' trihull to a 28' cruiser with two 350s. What do I need to know?

My current boat (also first) is only a 14 footer, but last year we were in florida and we rented a 21' cc for the day. HUGE difference, too alot of getting used to.
 
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