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obct said..
I'm a fat old guy who can't surf to save his life, so you can take my advice with a grain of salt, but here it is anyway.
The rail profiles you need may not be too different from the sups you've owned. You mention nothing about wanting to nose ride, so 50/50 rails won't be needed.
The rail at the nose can start off evenly rounded and then from around 15inches back, they could start to drop to a down rail, not a hard edgy one, just a nice subtle rounded one.
The rail woul need to get harder at the rear, but you probably would not notice it start to happen until around 16 inches from the tail.
The tail is where I differ a lot from conventional wisdom, most modern boards has a slightly squared off or boxy tail, it's to induce speed vai a phenomenon with a weird name, I don't subscribe to it for a longboard with a single fin, I like a heavy foil that thins away to a sharp edge at the back. I feel it gives me the feel of having multiple fins in a turn.
For the bottom I prefer a very sallow bouble concave stating jut behind half way and running out to a slight vee tail.
Template would be pin tail for decent turning on a big board
I'm not sure about the entry I doubt you'll need a concave, but then, I've never enjoyed riding hullish boards. Maybe flat, with just a hint of a conc
Thanks for your input, obct.
I forgot to include in my details, that i don't intend to noseride, my 9'6 already fits this purpose, at least, for my shaky attempts at the forward quarter. Also, i weight 80 kg and no wetsuits are needed here (Puerto Rico).
I prefer a bellied nose instead of a concave because of the smooth paddling experience with my prone paddleboard, a Bark Commander. That thing just motors against any chop and wind ! And glides like a damn torpedo. I can surf it on very small swell, downwind or on the summer flats, but on knees.
On the other hand, my 9'6 longboard features a wider nose with a concave and chines. And it slaps quite a bit whenever the chop shows up, specially when paddling back to shore against the ever present and early rising wind.
Since the outer reefs i plan on surfing on the glider are way offshore, i would definitely prefer a great paddling board to get there and leave the concave nose board to surf the inner reefs.
Do you have a picture of the foiled to sharp edge tail design you favor?
I concur with you in that really thinned out tails work wonders for reducing drag and enhancing glide. This is a picture of the tail on the prone board i have. It glides beautifully, and does initiate a turn. It is a really narrow board, at 20" wide, the tail tapering to maybe 6 or so inches. There is not a sharp edge in this bottom, other than a crest that starts behind the fin box and ends at a very sharp tail. I love pintails, no doubt.
Regarding the bottom, and making reference to a nice sup i once had, an 11' Alii Takayama, that board had no sharp edges anywhere, had a rolled bottom in the midsection, and the rails, started to become more defined (not sharp) in the rear, around the sidebites area, just as you explained. That board was an excellent glider, but, at 28", too wide for a prone paddling glider. Had to let it go when i hung up the paddle. I would prefer something in the 23" width.
You mentioned a subtle concave, in the midsection. Would be interesting to know more about this feature, regarding depth, how wide, if chines come into play, etc.
I really appreciate your wisdom in this aspect, since, as i said, i've seen no long gliders here.
I believe that extracting design features from other craft, such as the prone paddleboard above, might help in the design process, but it might also not...it's a gamble.
Thanks, be well.
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