cathedral hull

[limeyboater]

Hi Gents<br /> great forum , im new to boating and have had loads of questions answered through browsing the posts, could anybody tell me if a cathedral hull is displacement or plaining ? I think i know the answer, and probs got too small an engine yam 25 on 18 ft boat(fuel is a big issue over here and im a lowly tinbasher ). what do you guys think?

 

[DJ]

Re: cathedral hull

It should be planing.<br /><br />A 25 on an 18 ft. boat might not provide the power to plane it though.<br /><br />A "lugging" 25 will use more fuel than an efficiently running 70.

 

[umblecumbuz]

Re: cathedral hull

Hi Limey,<br /><br />What DJ says ...<br /><br />Just now and then, when I can't think fast enough to make an excuse, I carry a couple of old folks around for a peek at the creeks and inlets hereabouts. We don't plane, because they don't like it 'bumpy'. We just potter.<br /><br />Normally, I'm howling everywhere on the plane as quickly as possible.<br /><br />I can watch the fuel guage sink to zero faster with them on board than I ever could with me gunning it!

 

[bayman]

Re: cathedral hull

Yep, it's so much more efficient to just push a boat around. Pushing tons of water and a boat ...not so good.

 

[b.gagnon]

Re: cathedral hull

I had an 18' boat and the mfg said no less than 80hp to plain, but that was a v-hull. I dont know if that would apply here.

 

[limeyboater]

Re: cathedral hull

thanks fellahs, thought as much....looks like im gonna have to push water about till i can find some money, anyone wanna buy 4 kids !!! what hp do you think i,ll need. I know weight comes into it but frankly i have no idea what weight the boat is (its been in the water all the time since i got it).

 

[limeyboater]

Re: cathedral hull

bugger

 

[CATransplant]

Re: cathedral hull

What does the specifications plate on your boat say about maximum horsepower? Generally, you'd want to stay within 75% of that power to get really decent performance. <br /><br />Also, what is the make, age, and model of the boat. We might be able to give you some idea of power requirements for satisfactory performance. <br /><br />Finally, is this a true cathedral hull or what is more commonly known as a trihull boat? Trihulls are generally fairly easy to plane out. The true cathedral hull has the three sections almost the same size. Trihulls generally have one larger central v-hull, with smaller outboard hull forms.

 

[CATransplant]

Re: cathedral hull

One more thought:<br /><br />If your 25 yamaha is a late model, and in good condition, you might well be able to swop it out for an older, but larger motor. It would be worth a try.

 

[limeyboater]

Re: cathedral hull

thanks C A. I have a prob with a lot of the original manufactures (sp)info cause the boat was originally an inland cruiser which had an inboard screw type engine,But it was the first cathedral type hull in the UK (built for stability with a shallow draft)and most people removed the inboard engine, removing 1/2 a tonne of weight, Leaving a mongrel boat with no guidlines for an outboard conversion. it may be a tri hull ,thanks for the extra spanner, so to speak,I think I will drag it out the water and give you fellahs more info <br /><br />ONCE AGAIN THANX

 

[Solittle]

Re: cathedral hull

cathedral hulls usually have much more cockpit space than the "normal" planing hull. They can give you a much rougher (and wetter) ride.

 

[umblecumbuz]

Re: cathedral hull

CA,<br /><br />In the UK, the regs on weight and persons carried ain't what you're used to.<br /><br />Many boats don't have a spec plate, or stated restrictions on weight, power or persons.<br /><br />You pays your money and you takes your choice!!<br /><br />And also in the UK, possibly because of high fuel prices, outboards are much smaller for the size of boat than in the States.