Steps wrote:
What total gross weight with ppl etc do you recon it will be on the water? What speed do you realistically recon it will get over the bow wave on the plain? Havnt done this sort of old school hull or looked into them. It is a plaining...yet,. going of my dads old clinker 25hp @the powerhead.. not prop.. it was more a displacement to semi displacement, which is a total different kettle of fish in calculation.. formula.
Messed with some planing hulls trolling as displacement , semi displacement.. defiantly hull length a serious factor.
Would like to play with some numbers. I have no accurate data base of similar hulls to even estimate hull constants on the plain. I would certainly not take the results as anymore than a very generous ball park.
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Have a bit more information here. 260kg is the calculated hull weight: Okoume plywood, epoxy, glass (calculated at 40% glass content) and some fairing putty only.
I will be running glass up the topsides (specs say only hull bottom) and will probably put another layer on the bottom. I'll also glass the sole with biaxial. I may or may not put a light glass (100 or 200g) on the cabin roof and other places. So add about 30kg there.
I'm using Meranti for the hull panels and frames/transom. Add another 25kg or so. I'm planning to buy Okoume for the rest but may not.
Add another 30kg-50kg for a couple of side benches(storage for tote tanks/ice box and leaning post for me.
Add 50kg for rigging/steering/gauges/fishfinder/hatches/bunk cushions etc.
Add 50kg for anchor and batteries, 20kg each for up to two tote tanks (full.)
20kg ice, fishing gear, food and drink and other misc.
150kg for a BFT, 125kg for a Marlin

, 400kg for a sword... or not.
110kg for a 60hp outboard,10kg for aux.
Subtract 10kg for not putting the rear lockers in, and if I manage a better than 40% glass content. Possibly subtract more as I plan to build the cabin from 6mm ply glassed with a light cloth rather than 10mm ply.
85kg for me. 140kg approx for two/three others. (This could be more, but then it could be less.)
Add that all up: 845kg, call it 850kg. That will put the sole right at the waterline, unless I raise the sole. There is room to raise it 2.5cm or more. The PPI is 350pounds, 160kg per inch. Cockpit depth is at least 640mm plus any coaming.
Currently I don't really plan to raise the sole much if any. I will run elephant trunk scuppers out the rear, a bilge pump for leakage, and possibly side scuppers that will be plugged almost all the time. The side benches will be designed in a way that they act as temporary buoyancy chambers in the unlikely event of a swamping.