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.
-Note by tjp7154
The underwater dash can actually be done in ANY direction. This enables Samus to move quickly through water and cover large horizontal distances.
To do this:
1. Hold the L button down and the direction you want to travel.
(The following steps need to be done right after each other. It will take a little bit of practice to get it correct.)
2. Press and HOLD the R button(all the way down) and tap(or hold) the B button AT THE SAME TIME.
3. Immediately release the control stick and Samus will dash in the direction of the control stick. This step will take a little bit of practice. Always keep the L and R buttons press down so she doesn't lost momentum.
4. For the second (space) jump, continue to hold the L and R buttons and just tap B.
Further note by: tjp7154
It is ALSO possible to dash in one direction, then dash in a totally different direction. (This requires MORE practice)
Just Dash in one direction using the first jump, release all the buttons on the controller, then dash in another direction using the second(space) jump.