After booking a few trips through E-plus, we have come to notice that not all trips are with them ie. dolphin swim at Isla Mujeres and the party hopper tour. Both me and my girlfriend were wondering whether to book through the links on the Cancuncare site, do they work in the same way as E-plus? (We want to be sure with pre-payment). Could we book these trips with E-plus of which, do not require pre-payment? Basically we want to know that we are safe paying up front with them. Any thoughts?