I made a anticav pan!

[THCL500J8]

This is what seams to be most effective

[headdownarseup]

Don't mind me, i'm just taking notes on all this.

Similar probs with my boat, badly trimmed, poor weight distribution etc.etc.
Starting to make some headway in some areas, but others are down to design of the hull.
Experimenting all the time though...
All good (mostly)

Jon

[Dinghy fisherman]

Thank you Charles for such an informative reply to my question.

re: weighting the bow. This is what i have done to my 8ft dinghy by placing fixed ballast, this has made a huge difference to how it rides when under way as without this it was just to high at the bow and too bloody lively on the tiller.

Again, thanks Charles

[headdownarseup]

My boat (17 foot cabin cruiser and quite heavy for what it is) ) tends to end up with a bow down attitude. Nose heavy?? despite having most of the weight in the back of the boat!!

The other thing is the motor is not mounted as vertical as possible as it could be, even though the rake is set OUT as far as it will go.
I'm going to have to carve a block of wood into a wedge to allow the motor to hang vertically on the transom, then i'll do some testing to see if things have improved any...


I hadn't realised just how critical it is to set the motor up perfectly to the transom.

As for an anti-cav plate, i don't think i will be needing one (but you never know)


Jon

[JERSEYMAN]

Trim.........

[headdownarseup]

Thanks Rene.

Middle set of pics is how my boat seems to be running at the moment!
Even though the thrust block is set as far out as possible, it still isn't enough.

I'm re-thinking with a block of hardwood cut into a wedge "sandwiched" between the bracket and the transom. This way i can set the motor to vertical (first set of holes on the trim setting) with plenty of option to go outwards more if i need to.


Jon

[Charles uk]

Your problem might not be the motor angle Jon, it's probably designed for the weight of a 15hp + motor & to run at more than 5 knots, some time after 5+ knots you will start to get bow lift.

The bow down attitude doesn't matter, when the only time your going that slow is when your driving in & out of the marina, when it's fitted with the correct size power unit.

[headdownarseup]

The thing is Charles, even when the boat is completely empty, it sits very level in the water.
The transom has got quite a bit of rake to it, so even when the motor is adjusted OUT as far as possible, it's just not quite enough. (i know that now)

I've done some quick measurements with brackets and levels and come to the decision that with the thrust block set to maximum OUT on the bracket, (century/102) the motor is STILL not vertical by around 15 degrees or so, maybe a bit more. Hence the decision to make a wedge to get things more or less vertical to start with. Can't do any harm can it?

It was only A-J that commented earlier this year that he thought the boat was trying to bury itself in it's own wake?
ODD as i was carrying some (ahem) "heavyweight passengers" in the back all the time, which should have offset this a bit.

Interesting that you mention about a heavier motor, as the boat originally came with a 40hp merc which i never could get to start, let alone run!

I'll have a look at the weekend for some wood to carve. Should be fairly easy to sort this out i should think.


Jon

[JERSEYMAN]

So Jon, you went from a 40 Merc to a Seagull 102....respect!

[Collector Inspector]

So how is the Pan going?

I am going to copy what Olympics have.

B

[Nudge]

I got another 2 1/2 knots out of my boat by adding one..... things may still change with a full tank of fuel in the bow.