I did next trial with 6HP outboard motor at full speed.
Now I know that maximum speed on for this type of hull , with 2 persons on-board is
about 20-21 km/h.
Possibly some improvements in efficiency could be made by covering holes in the hull for dagger board.
Maybe also by extending that stern part of the hull by 1 -1.5 m and shaping into sharp pointing like a front the hull. Should minimize the drag.
www.google.com/maps/d/viewer?mid=1lEScYKY5wLPse_7sZtaExsMKS2w&msa=0
This week I should be able to attach electric motor for first trials.
For memory if you round off the stern of the boat you will turn the hulls into a semi displacement hull instead of a planning hull and you will loose speed.
Same as the prop on your outboard - it needs a sharp trailing edge to reduce drag.
You would be quiet surprised how tinkering with the prop will better suit your application- not a heap but something.
You could use the centre boards and turn them into hydrofoils quite easy attaching wings to each board but you would need to do the same to the rudders to lift the stern.
Also a alu v bottom will plane at 17knots with 60 kg onboard with 5 hp a flat bottom inflatable may cavaitate with the same set up.
I would save your time on the hydrofoil. To much drag - good idea though.. Could see that working with a 15hp and up long shaft - now that would be fun.
Aluminum boat faster in smooth water with no wind.
Inflatable flat bottom, faster in small chop, smooth water with up to approx 20knots of wind.
When I read your posts the voice / image of you I have in my head is Manuel from faulty towers. Not even manuel could conceive such a rediculous contraption or waste so much money on it. Whatever gets u up in the morning tho..
but what skeleton support do you Mark suggest for the poly core deck 2.4 x 6.0 ? Because whole lot will be enclosed in aluminium frame around I could obviously do supporting bars beneath every 1.0 m across and one long in the middle.
I would recommend that you look at this site for some idea's.
endless-sphere.com/forums/viewforum.php?f=39
I have been building electric bikes for a few years and can only say the batteries are the single most important issue you will need to get on top of. What is being achieved in high end electric bikes is just amazing and the speeds and distances make them a real alternative for transport, but thats another story.
The cell technology out at the moment is very good and can be had cheap. If you could you should look at some A123 20A/h pouch cells and build your project around them.
The cells will dictate a lot of the performance of the craft so you may as well stay within the parameters of them.
Good luck with the project.
At this moment the main problem I have with outboard motor is terrible splash.
When mounted on the rear beam.
All incoming water is attacking that motor leg at high speed.
I did try my 6HP Suzuki and 18 HP Tohatsu.
On my dingy propeller sit just below hull and leg is protected , water level precisly as should be.
In catamaran propeller is at different depth all the time on our bumpy water.
That is why catamarans have usually propellers at each hull.
Maybe later I should use two electric motors instead of just one, or one sitting at the end of the very long straight shaft - like those used in exotic Thai boats.
another option could be addition of sharp pointing protector in the front of outboard leg to protect from incoming water.
Generally speaking ride on this converted catamaran is very comfortable on moderate bumpy water.
I did try same motors on my other inflatable 3.6 m boat.
For 6 HP dingy is almost useless because planning is possible only at very smooth water, So with small motor catamaran wins hands down.
With bigger both boats go easy above 30 km/h , but unless the splashing problem is not resolved the ride on catamaran is not fun at all
