supra power loss on take off

alright - i searched through the archives, but couldn't find this problem...

bought my 2002 supra ssv last month. took it out and it ran great all day. near the end of the day, when first hitting the gas to pull up a boarder, the boat bogged and lost power, stalling out. after once more, i decided to call it a day. the boat takes off smooth with a slow accelleration, but not on a full blown take off. people told me maybe bad gas.

next trip out, i was nervous so filled up with 93 octane and poured 2 bottles of fuel injector cleaner in. it took a while to start at the dock. ran it for about 20 minutes, then gave it a 'test pull'. it bogged, died, and wouldn't start. a fellow boater came aboard and helped start it. even with choaking it we could not smell any gas. spraying starter fluid would help it start, but it would not run. figured fuel pump and maybe water seperator...

took it to the supra dealership and they ran it on the machine with no problems all day. said they could start it easily and run it repeatedly. now they want to drop it in the water to test, which is a $150 charge. i am going to have them do it... but what do you guys think is wrong?

sediments in the fuel tank? fuel pump? timing issues?

PLEASE HELP!!