I've never owned a polespear I own 3 spearguns tho, and I am a bit of a newbie to spearfishing myself.
When I was first looking at getting into spearfishing sometime round August last year, the guys down at my local dive store told me about a beginer/intermediate Freediving course that was to happen in November. (No Bubbles is the name of the company who ran it.)
"Son, Go Do A Course..." was the best bit of advice I've recieved so far, bar none!!!!!
I learned so much in one weekend. Proper breath hold technique, safety, breathing exercises, etc etc etc. Sure it's a bit of a cost but invaluable if you ask me.
I can now comfortably dive down to the bottom in 17m of water, and spend a good min or so waiting for that HUGE Blue Moki to swim a bit closer, or plucking 3 or 4 Paua off the bottom. (aka Abaloney for you non-Kiwi's).
Technique that would have taken me years to build up without the course.
