Scubaman's Quest 1.0 from Alive Software.
The coolest VGA Underwater Action Arcade.
This game features:  256 color scrolling 
action, Soundblaster/Adlib sound effects
and great music.  Three full underwater 
adventures are included.  
Collect rare marine creatures, discover 
lost treasures and many other surprises.
Armed with your stungun try to survive 
shark attacks, killer whales, angry 
jelly-fish, mutant squids, giant turtles,
hostile divers, mermaids and more.  
Also avoid those floating mines.
Requires: VGA, 286-16 and 530K of memory
Options: Joystick, SoundBlaster, EMS/XMS.