Permaid is the model in a gimp suit in the shape of a mermaid
Disclaimer: fish play and mermaid play are potentially very dangerous forms of BDSM, this guide is meant to be used solely as an educational resource, I am not responsible for how you play, I am not responsible for what happens to you in the real world, please do as much research as you can prior to engaging in this kind of play, get the proper health certifications (such as CPR), and never be afraid to dial your emergency hotline (like 9-1-1) if any emergency or medical situation pops up
Fish play is a type of pet play in the BDSM community. It deals with a person taking on the persona of a fish. It is arguably one of the more dangerous forms of pet play, since one of the fish player is typically (at least partially) submerged in water (or completely submerged in water). The fish player will eat food that typically resembles some kind of fish food, but is completely safe for human consumption (they do not actually eat food made for fish-pets). An alternative form of fish play is known as "mermaid play", where one person takes on the persona of a mermaid. They can wear a complete gimp suit (as Permaid is featured above), or can take on a more "traditional" mermaid outfit.
If a person is interested in mermaid play or fish play, it is absolutely that vital they feel comfortable in and around water. It is vital that they are a strong swimmer underwater. It is not recommended to have the arms and/or hands bound behind the person's back when in the water. Lets can be bound (like a traditional "mermaid") but it is strongly recommended to have some kind of fin (such as a monofin, normally about $40+) to give them an easier time swimming in the water. Do not swim in water where there is a current. The water must be appropriately warm as well. There are plenty of risks in swimming too hot or too cold water.
The Dominant of a fish play relationship could have a variety of potential titles, but one of the more popular ones is "angler". They will tend to their fish player, making sure that they are well fed, and can teach their fish player tricks in or right above the water. If the fish player submerges themselves into the water (fully or partly), it is strongly recommended to not play alone and to have them under close supervision (one never knows when a panic attack or similar could occur). If any type of binding occurs, it is strongly recommended to have a quick release knot (where the person can easily and quickly get themselves out of said binding). If the legs are bound by fabric, it is recommended to practice in shallow water to learn how to quickly get out of said fabric.
If a person is interested in buying a professional mermaid tail, please be aware that these tails are very expensive. The low tier tails tend to run between $150-400. Mid-tier tails tend to run between $500-800. Top tier (professional) tails tend to run around $1000+. DO NOT buy from "second hand" shops or websites (EBay, Etsy, Amazon, etc.). It is STRONGLY recommended to only buy from proper tail tailors (like MerBella, FinFolk, or MerTailor).
Fish play (as well as mermaid play) is certainly a more unique form of pet play and is not well discussed. This document is meant to serve solely as an educational guide for those brand new to fish play or mermaid play.