Ok I don't know how to ask this question, so I'll go ahead with the ex.

Player 1 : Has Catapult Turtle on the field.
Player 1 : Plays Another monster
Player 2 : Activates Torrential Tribute.


Ok now can Player 1 use Catapult Turtle effect and launch himself and the monster?

Yes he can........... it's just a matter of priority............ but there are 2 little things you have to take into consideration though:
1. Your only allowed to use Catapult's effect ONCE, so you'll only have time to launch one.
2. Since Player 1 activates Catapult's effect and then Player 2 activates TT, the chain resolves backwards, then there aren't gonna be any monsters to tribute.
Cheers...........

Thank You, thought so, but my opponent thought, thats not true, but I still won the game :)

Actually, isn't the tributing a cost?

That would mean that Catapult Turtle's effect goes into Chain Link 1 with the tributed monster and would do damage regardless.

Yes it is............guess I didn't explain that clearly =/ sorry........... I was just refering to the second monster tossed, because of the fact that Player 2 had a chance to respond with TT then the triggering Catapult for a second time wouldn't do anything.........since the monster wouldn't be on the field no more...

Not sure if this is right, but it's just nagging me, but if the opponent summons another monster AFTER Catapult Turtle, wouldn't the player's priority to use Catapult Turtle have passed?? (So far Priority player's have for certain cards only seemed to be able to be used when the monster the player uses priority of is the one just summoned)

Well Half remember that turn player always has priority to activate a Spell Speed 2 or higher t/s card or an ignition effect so after the summoning turn player would still have time to activate Catapult's effect, unless he decides to use or activate any other card or effect.....