I've replaced the old 6v sealed wet battery with a lipo 3s,11.1 volt 2200mhz, 100c spectrum smart battery. so the 1st run was cautious i just fired up the centre prop to see how she performed, well i was surprised at the turn of speed she had on just 1 prop, and how well she planed, it was a little awkward filming and controlling the boat by myself as i was the only one pond side. this was not without mishaps though, see 2nd video
After checking the boat over she was found to be unmarked and no bits missing, not bad to say she hit the pontoon at full speed, took off and plunged back in at the other side.
So the second run i started on the centre prop and then opened her up on the outer 2, she shot forward and immediately stalled, dead in the water. luckily i could reach her with the ponds barge pole to pull her to the side. i found the fuse had blown , i had fitted a 20amp mini flat fuse, i didn't have a 30amp only another 20amp which blew just as quick, upon opening up the outer props.
any ideas anyone or will a 30amp do the job, or a 2s battery? help any suggestions considered.
Roger

Part 1. ideal conditions; nearly 30°C, cool Bier at hand😜
Sea Scout built by Dad in the early sixties with a Taycol Target and 6V lead acid wet cells (very wet😡). Renovated and dragged into the 21st century over the last several months 😉
See Build Blog 'Sea Scout 'Jessica'' for details!
Motor: Propdrive 2830, 1000kV, 30mm 3 blade Raboesch prop. Quicrun 16BL30 (30A) ESC with BEC.
Tested with 3 battery types, all started with 99% measured capacity-
1. NiMh 4.2Ah 7.2V, nom. 408gm.
Result: Speed sedate (OK 😉scale river cruising!) No planing.
Max current: 3.6A
End status V / capacity left: At end of short run ca 3 mins. 7.78V 99%.
2. 2S LiPo 4.0Ah 7.4V nom. 257gm.
Result: Speed still sedate but due to lower batt weight at least the forefoot came out of the wet stuff! Max current: 4.1A
End status V / capacity left: At end of short run ca 3 mins. 8.25V 93%.
3. 3S LiPo 4.0Ah 11.1V nom. 315gm.
Result: Now we're getting somewhere!!😁
Good speed, manoeuvrability and planing 😊 Max current: 7.5A
End status: 11.95V 74% after several long runs, ca 20 mins total.
Estimated (extrapolated) endurance on a 4Ah LiPo around one hour - mostly 'full bore' - 'Pedal to the metal man' 😊

See also:

The competition!

Final run. (Beer was getting warm😁)

Cap'ns log entry:
Boat dead-weight w/o battery: 1.8kg.
Spray rails to be added!😲
Slight list to port to be trimmed.
Rudder servo to be reversed!!😲
Keel protection to be added: some scratches and flaking from stony sloping shore 🤔
Summary: much as expected👍 Forget anything less than 3S.
Anyone want to buy a batch (4) of new 2S 4Ah 45C Lipos? 'One careful owner'!
Happy boating people, Cheers Doug 😎
PS Many thanks to Camera girl Gisela 👍
Recorded in 1080p HD.

well finally got there. she sits a little low in the water, but evenly along the water line. this was with the battery central to the hull. when powered up the centre screw alone moved her quite serenely and was very manoeuvrable. when power was added to the outer screws I would say she didn't plane well as she wasn't going fast enough. even with all props on full power, I think also she is to heavy and the battery too far forward.
So to remedy this I moved the battery back a compartment, positioning it over the 3 motors , it was a tight squeeze, but fitted just.
This sat the stern down a little and the bow up and gave the impression of planeing, she still not fast enough though. the scale speed still doesn't look right.
I'm going to have to have a rethink on this one. having said all this though she looked well in the water if i say so my self.
Roger

Set the new Surpass 3000KV 36 diam finned in-runner up in the boat, and did a tank test. Lots more power than the HV brushed 1200kv 550, but with higher idle. Re-did the reinforced silicone coupling and fitted a small collar to the inner end of the motor shaft to hold the tube from moving forward against the motor, as with the extra torque of the in-runner, it was trying to twist the tube off the shafts. Seems to be hanging in there static which is a promising sign. Once running, the load will come off which should help.

Runs full at around 4A and the battery holds at around 3.8v/ cell )alarm is set at 3.6 for safety, (as a sort of rev limiter) performance should improve a bit now. Have to wait till tomorrow as the restrictions end at 6am Sunday, (then have to hope for good weather for the test) The prop in the jet is a 28mm 3 blade racing prop which I modified to fit. Don't think I'm going to get much more out of the jet unit without it exploding😁, (it's only plastic I think, not GRP), - might have to buy a back-up and fit it with better quality bearings etc. If the jet was in the usual 'plastic' 24" toys it would be a rocket, but it's pushing 6lbs which is a challenge😀

Note the police chase outside in the background😁- always action around here, lots of hoons in cars😁

I trial fitted a thermal switch to the fans in the dummy motor, which is mounted on the 540 motor. It starts the dual fans at 30deg C and switches off at around 20deg C. Bit hard to hear in the vid (plus the YT transfer removed the middle of the vid, -there was a gap before I put the soldering iron on again,- and at the end don't know why it does this, - doesn't like the format I think😠) Anyhoo, not doing it 3 times! (clipped the end 10 secs off the previous try as well😠)

Fan switch is powered at 8v via a small voltage reg from the main battery (3s 2200 20c) and works pretty well. All fully hortomatic like😊

Finally got a good day, so raced down to the pond and threw the boat in. 2 problems, 1: battery had run down a bit with all the testing, and the new 18kg digital servo winch needed every bit of 4.8v, so functioned intermittently, meaning not much sail control, 2: jib boom needs a kicking strap to stop it 'skying' and tangling (knew it would happen but wasn't a worry). Apart from that, everything worked perfectly ( cheapo China Futaba knock -off rudder servo still worked fine on the low battery which is a bonus)

Sailed brilliantly like it did over 40 yrs ago, and as it's set will sail hands off on a reach, being nicely balanced, (even with the crappy jib,- which I had to make,- well actually my mother made for me,- back in 1980 after the original was stolen by a kid at the beach, while my back was turned😠) Funnily enough it was made on the same Bernina I used to sew (horrendously) the jib foot after trimming it for the boom a few days ago.

A few more things to improve and add, but pleased to have it back on the water. Another crap video, -seems to get blurry once it's been through the movie editor and You tube ) One day santa might bring me a Gopro, ("yeah right"!)

Managed to connect up the motor once all the drive bearings were in.. first video is with a 7.2v battery (which was actually nearly flat!) and then in the second video with a fully charged 11.1v lipo!
Might get the Atlantic RIB to plane yet..

3 GPLs on the lake at once, all with different engines, 2 with onboard GoPros, 1 unfortunately with a battery that was about to fail...

She is a bit tender as the 12V battery makes her top heavy. If I lay it down she is bow heavy...will sort that out I redid the wiring and lighting

Made a few adjustments, including alloy braces for the motor pylon (was a bit flexible and I think it was twisting slightly under power. Rudder linkages still need tightening up (crappy HK clevises,-probably will fit ball links) but it was a bit better this time (apart from a high speed excursion into the rushes at the end,-no damage, got in the shadow and brain couldn't calculate time, angle and distance😁) Battery was down to 7.5v/cell after all this (4000mAh 3s) so not a bad run time. Only had full throttle for about 3 secs total, -too hairy!😁 Put in expo and dual rates but that didn't do much (too much rudder slop to be accurate). Back to the mod shop.

This 'Whaleback' boat is a 1/16th scale Air Sea Rescue Launch that was built by a friend of mine Graham. It is powered by a Turnigy brushless motor and Lipo Battery

Just a short video of some of the boats at the show, camera battery let me down, but you might recognize a couple of the boats that were there.

Cheers, Pete