But surely it is better to go for an aircraft with a larger carrying capability and not have to use that capacity very often, than have one that will have to keep going back to shore for fuel every 2hrs?
In your scenario there would need to be several aircraft.
3D Your'e confusing capacity with endurance and not addressing the question so I'll ask it in a different form. Given that there is a finite budget, how big is big enough?
Zalt, again the same problem, no helicopter is big enough all the time, so how big is big enough?