Hey Chuck, that sure is a keen machine! That 1st flight sounds kinda like my 1st one w/ my Seamonster! I think I have a little + incidence in the wing saddle, or the stab. ain't on quite right. Mine was also a bit tail heavy[X(] and was like a roller coaster ride.
Do you have any problems with the props being close to the water? I'll bet it doesn't waste any time taking off when you pour the coal to 'er! If you do get bored some day, make sure you get some video so we can see what a 3 engined SeaMaster looks like!