Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit the "easy-cfg.xml", "normal-cfg.xml", or "expert-cfg.xml" file (for the corresponding difficulty setting) in the "data" directory of the game folder. Scroll down to the "Default" section and find the following text:
Change the "DiverSpeed 0.300000 /DiverSpeed" entry to "DiverSpeed 9 /DiverSpeed" You will now go faster than ever. You can also change other things, such as Ocean Depth, Treasure Secs, etc.