HI Ian
See you are making good use of the wattmeter 😀
Like the video and agree the balance could benefit with a bit more weight amidships.
Listening to the video sound suggests your motors are not developing full power so I suspect the NiMh's are not capable of delivering the amps required.
You could try smaller props with the NiMh's to see if the performance Improves, could be your motors are working just below the optimum.

Dave, I found that the Nimh batteries were dropping off to around 9v at full power when measured with the wattmeter and this is why I want to go for Lipos, one on each motor. At the moment I'm taking everything from one pack and I think this is the limiting factor.
When I get my Lipos I will stick them in the middle and try larger props, probably 40mmS types to begin with, having measured what's going on with the wattmeter first. it may be that the existing props will do better if the batteries are delivering up what the motors want. You're right, there is still plenty of headroom with this setup.
Just got to rake up the cash for two largish capacity Lipos!

The wattmeter is a splendid purchase- I'd say essential for this type of thing.

Anyway, glad you liked the video- she still looks quite good toodling around at that speed.

All the best...Ian

It's Beauty !! 😋

BRAVO ZULU! She's superb!

Looks exciting. Are Tunnel boats more stable than other types?

They can be very stable and get a higher level of speed over a mono hull. BUT ...... yep, there always has to be one............ I find that a mono hull can sail in any type of water condition, twin hulls, or tunnel hulls are better suited for calmer water. the main risk is for the hull to flip over backwards if thits the crest of a wave and the wind gets under the bows, the centre section then acts as a sail , wind catches it and lifts the hull nose up........... and over !

If you get the chance to sail one.......try it, they are good fun to sail, take a bit of concentration to get the best speed out of them, especially on turns.

Its like any boat, there are good things and bad in all of them to a degree.

Brian,
Ouch! Sounds a bit expensive.On the advice of Dave M on this forum I bought myself a wattmeter and it certainly takes the guesswork out. I went through three esc's on my Lesro Sportsman before I got it right- hopefully! Also spent a good deal of time anxiously waiting for my Rapier to drift back to shore after it popped a fuse- twice. Now I know what the limits are and I just didn't have a big enough fuse in.

I'm having just what you describe with batteries being too far astern- I'm going out Monday to try them in the middle of the boat. Also hoping to get some LiPos when I have decided on a make.

Hope the new motors and fans work out and that you get some good shots on the water eventually.

All the best...Ian

HI Ian, well the original motors came from a discount store, £2.00 each from memory, they work Ok in my USS Crokett, but I have no glazing and the hot air can escape! I think the sequence went like got hot, melted fan, fan fell off, jammed Motor, fuse blew. I couldn't get any water cooling pre bent from Westbourne so will make my own tomorrow. I have opened up the funnel a bit more on the side and place louvres over the hole, I will get a photo. I did use LIPOs (turnigy 3cell 3500) but now have gone over to A123's much better I have 3 in series X 3 in parellel Giving 6600 MAmps @ 10.4volts.These are very safe batteries, almost unbreakable, I use them in my planes they weigh a little more than LIPOs but a lot less than Gel cells about a quarter and can be forces charged but you would have to sail all day to flatten them. Thanks for your interest, speak to you soon, Brian

I would try and leave the cooling slots fully open, to allow air to circulate through the motor internals. Same goes for any air slots in the front face of the motor, always try and make a hole on the motor mount [if none in], to aid airflow through the motor.
if you cover the slots up, you are only adding to the internal temperature of the motor you are trying to cool.

Thanks. I suppose it's obvious when you think about it. The motor mounts do have slots in the front face.

Mmmm.... turn fins? Perhaps he means a 'dagger plate' a vertical fin that should help prevent the boat from rolling and filpping on turns. Just theorizing I'm not sure though if two would be the answer, I wonder if they might actually hinder. With a single plate of the right size placed centrally the boat would be still be restrained from too much sideways roll yet not lose any directional control being able to pivot on the single plate, where as two plates would tend to act like two fixed rudders and be hinder to turning. I also fly planes and I agree with Dave M about fine control, if using a computerized radio dialing in both rates and expotential helps compensate for over enthusiastic waggling of the sticks and is nearly always required for fast craft particularly first time out. Anyway that sure looks like fun, that's a serious handful and on just 7 volts, well done!

Dagger boards are onl;y used on sail boats, turn fins are a fine edges plate, fitted to the transom, and adjustable in height/depth to the water, so it gives less "bite" when running straight, but digs in on turns to get the hull to bite in to the water.

A rudder is fitted, so there is no way of fitting one of these centrally my freind, they have to fit either side/one side of the transom.
"trimming the radio" does not cater for the movement on a fast boat, thats purely down to the person behind the sticks at the time!
The "end game" on the video was when the rudder dug in too deeply and the boat just spun around due to an "over steer" moment........... thast just what can happen when playing around setting up brushless systems.

Reminds me of my old navy days!

BRAVO ZULU! REALLY COOL SIR.

Thanks Dave

The Fireboat had it first run yesterday with the donated Johnson 888 motor and the original prop. Speed was satisfactory, just nicely on the plane and the battery lasted well, a 7.2V Nimh 3000, so I am happy with that. Controller was a donated Robbe minI 200. Unfortunately although this gave speed/stop control there was no reverse. it has pot adj for 'speed' and 'stop', which I adjusted, but Perhaps it was never designed to give reverse?

Another project is a very old 1950 damaged 'ASL'hull. I have the original drawing titled 'British Power Boat' who were the builders in wartime. it has a 'whaleback' cabin surmounted by 2 machine guns in turrets. These I have cut from radio valves.
Its a most unusual looking boat.