Exactly. When a hunter kills a seal, it means it's necessary, whether for fur, meat, fat, etc. When a tourist does that... he kills the seal with little skill, causing it great pain, damages the fur, and probably does nothing with the carcass later.
It's okay for hunters to kill seals for sport, but not for tourists to do it?
If a hunter kills a seal for sport, it's not killing it for anything necessary.

I am not against seal hunting if it is not excessive and it is done for food (well, now Levian just said seals are edible). I mean, if you can use the seals for the meat and the skin, then it's OK, as long as it is controlled and they don't end up getting the poor animals extint or screwing up the ecosystem. However, if it's just for the skin, yes, I find it unethical.