Underwater Dash
Discovered by: BoostR
Variations by: Red Scarlet, Bartendorsparky
This is a trick enabling Samus to travel large horizontal distances underwater, in a similar vein to the huge leaps possible with the dash jump technique from Metroid Prime 1. This technique is also possible on land, although it does not seem to provide any more distance than a normal space jump.
This description assumes you wish to jump from right to left (i.e. your target for the jump is to your left).
Hold L. Begin strafing to the left. Press and hold R (all the way down) and B while continuing to hold left. Samus will begin to turn to her left. When Samus has turned through about thirty degrees, continue to hold L and R but release the control stick and B (just take both your thumbs off the controller).
Upon removing your thumbs, you should find that Samus continues to fly through the water in much the same way as for the original dash jump.
For the second (space) jump, continue to hold L and R and just tap B. Don't adjust the control stick or press anything else or you may lose momentum.
This trick can be used in Torvus Bog: Hydrodynamo Station to obtain the Grapple Beam without Boost Ball, Gravity Boost or Seeker Launcher.
