Advice for LARP NPCing of sorts?

[Joy&RaptorsUnrestrained!]

Hey all!

I'm going to be attending the Stormwrecked! LARP over Halloween weekend as a player, taking on the role of a shipwrecked navigator who is gradually turning into a flying fish. Originally, there were intended to be mermaids and sirens in the NPCs cast for players to interact with and to provide or take away resources from the three crews shipwrecked on the island. But because they reduced the cast and players to keep it at 50 in case COVID gathering rules are restored, things are a bit tighter, along with a number of people dropping out because of concerns for their health and that of their families (the game is going to provide masks as an option and consider them part of the costumes, and everyone has to provide proof of full vaccination, though).

Apparently the person they originally had who was going to play some sort of merfolk is no longer attending, and the other NPCs aren't comfortable in swimwear or in the water. The game designer doesn't want to pressure any of the NPCs to do it if they aren't comfortable, and the fact that I'm experienced swimming in a tail and enjoy it provides a solution.

I'll be acting as either an NPC merman or my own character, and bargaining with the other player character or sending them on quests to retrieve things for the merfolk in exchange for some rewards the teams can use.

But I haven't really done any mermaiding for anything that wasn't my own fun. Any advice for mermaiding for a LARP?

[Merman Storm]

Understand the mechanics of the game system. Understand your part, and all the details around it. Know enough to deal with odd questions coming from the payers, and what to do in odd situations, like getting "attacked".
Have something to do when the players are not there. There can be long boring periods when they are off doing things other than interacting with you.
If you are going to be a mer, use your most comfortable tail. You may be in it for a long time.