I assumed that serious scuba divers were, almost by definition, deeply committed to reducing environmental degradation, and, hopefully, mature enough to understand that it is their individual responsibility to reduce the extent to which they personally add to the problems of global warming, pollution, destruction of the reefs, etc.
I can't imagine owning a vehicle which burns up great quantities gasoline. There are many reasonable alternatives. Not using these alternatives, even when they are somewhat inconvenient, runs counter to both self-interest and moral responsibility.
I know that very young and/or very stupid divers often have a narcissistic self-centered perspective, with no thought beyond their immediate desires and appetites, but I'm still astounded by the seeming inability of some people to see the connections between what they do and the destruction of what they claim to love.