i probably havnt used nearly the ammount of fins as many on this board, i started off using my bodyboarding fins (custom x) for snorkling.. yea sure i can move a bit faster on the surface with them, but my legs move a lot more ! underwater, more movement is not a good thing, especially spearfishing. with short fins, i couldnt effectively hunt parrotfish on my favourite ledge in 50 fsw, the best way to hunt them is to drop to the sand about 30 feet off of the ledge, slow descent, with very little movement (just twitching my ankles basically in the last 15 feet) when i hit the sand, i lay down on it looking at the ledge, then slowly use my fins to propel me towards it, this way, i imagine i look a bit less menancing than if i was hanging in midwater, and it does let me get within killing range of a good set of fish. longfins also have the good benifit of getting u back up to the surface, and fast, if you spend a bit longer than you anticipated on the bottom
. manouverability is an issue you touched on also, well, first time i used my longfins, i was like wow.. i think i ordered the wrong thing,shoulda got a pair of plana avantis (scuba fins) but now, ive learnt the limits of my fins, learnt a few tricks to using them effectively, and i do all the cave spearing ect. that i used to do with short fins, if i was twisting around on the bottom doing rapid direction changes, im sure id look like a pretty ugly shark to the fish anyways
keeping it slow and easy and relaxed is the trick to effective spearing, and longfins allow it in a way that shorter fins dont.