This question arrived via email: Which boat under 60 kg weight will be the speedest ? I just finding compromise between weight, motor power and speed
For example what's speed I can reach with one 65 kg person and two 65+75 kg persons and with 5 HP and 8 HP four stroke engine ? Give me four values for both models of boats, please. Jeff
„FS14, GV 10 &11 Questions” for Jacques
Re: „FS14, GV 10 &11 Questions” for Jacques
We only have a couple of dinghies that weigh less than 60 kg. None of them will plane with two persons.
Sorry.
Please do a search for "Crouch formula". It will show you a simple formula to calculate planing boats speeds.
You will see that your figures are extreme.
Sorry.
Please do a search for "Crouch formula". It will show you a simple formula to calculate planing boats speeds.
You will see that your figures are extreme.
Jacques Mertens - Designer
http://boatbuildercentral.com
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Re: „FS14, GV 10 &11 Questions” for Jacques
Dear Jeff and Jacquesmm,
thanks for Your help and suggestion "crouch formula" !
J just found simply calculator:
www.omnicalculator.com/everyday-life/boat-speed
8 HP engine, 245 kg boat displacement (boat 60 kg, person 65kg, person 75 kg, engine 25 kg, tank 10 kg, something light goods) should give nice speed 29-45 km/h !
What kind of hull do You recommend for recreation ? I'm thinking to build from plywood.
thanks for Your help and suggestion "crouch formula" !
J just found simply calculator:
www.omnicalculator.com/everyday-life/boat-speed
8 HP engine, 245 kg boat displacement (boat 60 kg, person 65kg, person 75 kg, engine 25 kg, tank 10 kg, something light goods) should give nice speed 29-45 km/h !
What kind of hull do You recommend for recreation ? I'm thinking to build from plywood.
Re: „FS14, GV 10 &11 Questions” for Jacques
Sorry but I can't design a hull that will go at that speed with a 8 HP.
The FS12 has been tested with a 8 HP and one person onboard and the max. speed was less than 15 mph.
With 2 persons, it will not get on plane.
The GV10 and 11 are good little boats but will not plane with 2 persons and a 8 HP.
The FS12 has been tested with a 8 HP and one person onboard and the max. speed was less than 15 mph.
With 2 persons, it will not get on plane.
The GV10 and 11 are good little boats but will not plane with 2 persons and a 8 HP.
Jacques Mertens - Designer
http://boatbuildercentral.com
http://boatbuildercentral.com
Re: „FS14, GV 10 &11 Questions” for Jacques
Thanks. Plane is a "sideslip" ?
So what's the minimum recommendation ?
Which boat will be quickest for example with 15 HP engine and one or two person ?
So what's the minimum recommendation ?
Which boat will be quickest for example with 15 HP engine and one or two person ?
Re: „FS14, GV 10 &11 Questions” for Jacques
Plane is about getting on plane. For a boat, it means the transition between turbulent and laminar flow. Once you get in laminar flow (on plane), you go faster expending less energy.
I assume that google translation gets us confused.
To the question: the GF12 would be a good choice to plane with a 15 HP and one or two persons.
I assume that google translation gets us confused.
To the question: the GF12 would be a good choice to plane with a 15 HP and one or two persons.
Jacques Mertens - Designer
http://boatbuildercentral.com
http://boatbuildercentral.com
- OrangeQuest
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Re: „FS14, GV 10 &11 Questions” for Jacques
How about reverse engineer why you need a lightweight boat to haul a large payload with a small motor but go fast. Then suggestions can possibly be made to fit your desires. With compromise, possible a lot.
Displacement hulls can haul more weight with less power, but hull length limits their speed.
Displacement hulls can haul more weight with less power, but hull length limits their speed.
"that it isn't just an ordinary sort of boat. Sometimes it's a Boat, and sometimes it's more of an Accident. It all depends." "Depends on what?" "On whether I'm on the top of it or underneath it."
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Re: „FS14, GV 10 &11 Questions” for Jacques
It is not just hull length but also the overall hull design that prohibits a displacement hull from planning. TomOrangeQuest wrote: ↑Tue Jan 17, 2023 7:36 pm How about reverse engineer why you need a lightweight boat to haul a large payload with a small motor but go fast. Then suggestions can possibly be made to fit your desires. With compromise, possible a lot.
Displacement hulls can haul more weight with less power, but hull length limits their speed.
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978
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Re: „FS14, GV 10 &11 Questions” for Jacques
Hmm. I did have a 2 stroke 9.9 on a GV10 for some time when our old 15 died. It planed very easily with 2 big (100+80 kg) adults and 1 kid.
So... maybe the GV10 would work with 8 HP but it would be close.
So... maybe the GV10 would work with 8 HP but it would be close.
designer: FB11/GV10,11,13/ HMD18/
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Re: „FS14, GV 10 &11 Questions” for Jacques
As another point of reference I once had a 2.7m Honwave inflatable with a 5hp four stroke Honda. At 27kg (OB) +10kg(fuel and gear)+ 33kg (boat) + 85kg (me) it would often, but not always get out of the hole and plane. That's 155kg for a 5hp outboard. Add even a small child at 30kg and it never did, not once.
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