what do i know, but on moving fish shoot for their "noses" and you'll probably end up with a nice gill plate hit.. works, sometimes, for me
PS: don't try to aim the gun. just point and shoot reaction style. Aiming is fine for static targets where you can straighten your arm, line up the sights, and squeeze the trigger (I almost said "take a half breath" before the squeeze the trigger part, but it does not apply too well
Without fail, every time I try to aim a speargun I miss. Most shots indeed are with bent arms and often at an angle to the body (hence: not aimed)
