I explain the bug I used in detail at the end of the Speedrun the run its self however was only about 1:25ish long. But to explain it briefly again, to my best guess, holding the underwater scooter (with left mouse) while holding space then letting go of left mouse will keep the momentum from the scooter giving you the height of about 3 jumps worth. Also its very easy to preform, since the games forces you to stop using the scooter at the depth of 30M making you automatically get the height of the jump. (assuming your holding both left mouse and space) also sorry about the audio book, I had to listen to something besides the water :D.

I think the fastest time possible would be 0:59ish, (assuming no bugs get discovered) but that would require some crazy luck, like a chest that had enough gold and copper for a underwater scooter that is on the way towards the base, and have the base spawn at the highest altitude (60-40m) now that I'm making the hypothetical example that run that I just described might be closer to 0:45, but that's basically impossible

PS Im shocked this game is still getting played! I didnt think I would ever have to submit another run, good to see it living. well. . . . "living"