Nice concept for the NM's

Perhaps a Fisher could charter/rent a boat with a party.
Leading to an instance where the fisher would need to haul in a mob (It could be a regular mob "Sea Snake", or it may be the NM "Ultros/Orthros") and then the party needs to battle it.
The would be a limit to the number of times a party could try to 'Catch the Big One' (Perhaps a limited amount of bait required could be supplied with the rental of the boat)
Fisher could have a net equipped as an off hand weapon and use it to temporarily disable the mob/MN allowing the party to conduct attacks.