Okay, I'm not an electric guy but I do know my way around a hydro. That said, I see some problems. Let me kind of go over a few:
1) What the hell are trim tabs doing on that boat? IF the boat is planing properly, they won't be anywhere close to the water so get rid of them, they're useless weight
2) RG is correct, the 3S packs are forcing the rear of the boat down due to the mounting location. This makes it harder for the prop to lift the rear of the boat
3) To go along with the battery location, the battery leads are too long. This causes higher resistance and less power to the ESC and motor.
4) The center of balance should be no more than 1" to 1.5" behind the sponsons. This, again points to too much weight aft.
5) Has that prop been sharpened and balanced? If not, it won't work as efficiently as it should. IF that prop is sized the same as an Octura, it's a 40mm prop with a pitch of 1.4 times length, or 56mm.
6) Have you removed, cleaned and greased the drive shaft? That is something that should be done before putting the boat on the shelf after a day of running. There are several light greases that will work well, just don't use a heavy grease.
That should start you off in the right direction
Just for the record, this is a .67 nitro powered 1/8 scale boat I've been racing the past several years. It's 43" long, 22" wide and weighs in at around 14lbs.
