cool concept, maybe enemies could sever the tube then you have to repair it to make it more challenging?
Thinking about the original posters idea of riding inside a whale. The devs could always implement a symbiotic bio-suit. A living animal biologically developed to encapsulate the user and protect them from whatever environment the suit was designed to be used with, be it water, or a space environment, or even atmospheric flight. Could also make one with biologic lights, thick armor plates, and enhanced forearms with claws for digging. Each suit once developed could be stored on the drop ship in a stasis tank that could be launched to the player on command. Plus the suit is its own lifeform so if it got to badly hurt you could return it to the ship to heal allowing you to explore elsewhere with other suits.
Right, but why would one carry a jet pack that only works over water, to use when they need to move across a body of water, instead of a jet pack that works over everything, for when they need to cross anything?