Slight weight shift on my 18 SC

[Beaver]

After installing a new fuel tank I moved the center console and the lean-to forward only 2 inches and moved 2 batteries forward about 14". I wasn't expecting much of a difference but I was pleasantly surprised. I went diving yesterday with the guy I normally dive with using all the gear we normally use (so it was a pretty good test). With two big guys, an ice chest full of ice against the stern and over fifty pounds in dive lead in the stern, the boat (with its little 3 cylinder) jumped up on plane significantly faster. I didn't even say anything. My dive buddy was the one who mentioned how much better the boat was getting up on plane. Just when you think it cant get any better...

I love this little Seacraft!

[Bushwacker]

Great post! I've been warning folks for years that if you take a hull that was designed in the 1960's for 250-300 lb motors and hang a 500 lb motor on it, you will screw up it's balance/CG and significantly compromise it's ride and handling! It's good to see you demonstrate what a big difference a small change in CG location can make!

[kmoose]

This was something I too considered on my Tsunami build and moved my 140 gal fuel tank foward to help compensate for the bracket and big motor. No doubt doing so played a part in the overall performance gains achieved.

The wild card of compromise has certainly been with the bracket though, Transition to plane has definitely been hindered as there is a speed "hump" that has to be achieved for the bracket to clear the water surface before she gets up. It seems to be more related to hydrodynamics than CG as once it clears the bow is glued to the water. I'm still experimenting with props and motor height. I think going to a 4 blade and raising the motor up a couple of holes will help smooth the planing hump out significantly and ease the transition. It's hard to believe how high you can mount the motor with the Hermco bracket and I am definitely running too deep.