You really wont die without this trick but it can help when try to maximize efficiency in regard to your breath hold. When it comes to spearfishing and scuba diving simply relaxing can really improve the amount of oxygen you use. Try not to have any mental blocks and if you do clear them or else you will never reach your potential. Kicking with long powerful graceful kicks improve your distance covered and also the amount of energy you use.
Just remember being relaxed will improve you diving dramatically.
spearosoftheworld 