"Yet each man kills the thing he loves
By each let this be heard,
Some do it with a bitter look,
Some with a flattering word,
The coward does it with a kiss,
The brave man with a sword!"
from
The Ballad Of Reading Gaol by Oscar Wilde
I'm just sayin'. If you're a vegan, I admire that enormously and would not expect you to enjoy spear fishing without significant ethical conflict. I myself have been assiduously trying to maintain a mostly plant based diet, with frequent dipping into the lower part of the ocean food chain: crustaceans and bivalves, squid, and some fish, plate size on down.
Since I'm already eating these fish (which I think is preferable to supporting the canned tuna industry and other non-sustainable fisheries) I can imagine no more ethically consistent practice than catching them myself. Trigger fish are an abundant reef fish in the Caribbean where they are served up as "Ole Wife" poached and smothered in onions and fish broth, or deep fried with a tangy sauce creole.
Sure they are beautiful, but so are many animals we consume. I never thought that was a fair standard for what was ethically acceptable to eat. My interest in underwater hunting is based in part on honing a skill set that involves stalking, navigation and significant maneuvering skills as well as a good knowledge base of fish identification and behavior. At least I so imagine.
If and when I get the opportunity to try it, I may find I feel much as you do: "not my cup of tea".
But I'd like to give it a go. I expect my main challenge will be not shooting myself in the fin!
Cheers... avra