I got curious and took my abandoned 1y old self build toy step up out twice last week after a long period of dis-use.
When it was first built I went through an initial period of denial before I came to accept it was a bad board. Some blame went on my choice of rear fin position. Because it was a round tail, I figured it could go up a bit extra from a squash tail. Then I thought I would add a little more because the tail was slightly narrower. Plus I thought my previous build was a little stiff. At 2 7/16" up from tail, I overdid the extra forward placement compensations was my feeling
There were other things that felt wrong too. On paper it had enough nose rocker when taking the tail rocker into account, but it felt like there wasn't enough at times. Also the front rails felt like they were too thin and on the verge of catching at times. It also didn't generate speed well in the sub step up waves I was trying it in. It wasn't intended for use in the lower end of the wave power/height range, but at that size and dimensions it should have been quite capable of generating speed decently particularly as it felt quite loose.
My choice of fins were AM small in FCS 2 box. AMs always work for me, my number 1 choice of fin, but not with this board. Further disappointment was that I had some fins custom ordered for this board. Greg Griffin fins and they did not help either and I put the AMs back in, gave it a few more goes then gave up on that board.
Fast forward to last week and some open ocean conditions with some grunt prompted me to give it another go. The Griffin fins went back in. One of the reasons why I thought the conditions were worth trying it again was that there was a light onshore wind which would mess it up a bit and there was a reasonable probability of getting it with few others out and not embarrass myself if I surfed terrible. I paddled out on my own into lefts breaking into a rip. First wave flattened out with a fast running bowly shoulder - this happens in the strong currents. I tried to generate speed and it outran me. Second wave I decided to put my foot right back and try and engage the Griffin fins a bit more seeing as my more forward easy speed position didn't work and the board really lit up
I also had an awesome feeling of slashing the tops off the waves backhand, the best that I have done since .. I can't remember. Someone else I didn't recognise joined me after a while and I managed to repeat the feeling on a few more waves before coming out of the water feeling incredibly happy.
Next day, a little bigger and messier with the same lefts breaking into the rip. No one out and a repeat of the previous session except when I felt the lack of speed generation on my first wave I quickly moved my foot back and didn't lose the shoulder. That feeling of slashing the tops off the wave backhand again and with the foot right back a feeling of drive. Both sessions confirm that it needs a tad more nose rocker and a bit more volume in the rails up front - this was evident when running into steeper inside sections.
I now want to make a version 2 for the Griffin fins. I spent this morning fixing up the flaws described in Shape3d. When I look at the board it seems to have too much concave in the fin area - more than any of my other boards anyway. I can't say I noticed any effects which could be attributed to that - board not skipping out or anything, but maybe it is the reason for its lack of easy speed - I don't know, I have taken a bit of concave out anyway and decided to move the double inside a single a bit further up the board. More mildly concaved too. Don't know when I will build it yet. Pictured below after last second session, prior to board swap with an Exile EX1 size medium.
Open ocean too big and blown out today, so going to take my regional custom HPSB out in sheltered cove.