One of the major change from Polly I to Polly III is increased use of fins. For aesthetic and practical purposes, Polly III will make more use of fins. Following is a summary on Fin Design Research.

1.Gill Fin

Installed on the side to give the fish a graceful gliding(swimming) look. Should be made from light materials for smooth movement. Possible candidate is the Orange fabric candidate from skin material selection

2.Dorsal Fin(Back Fin)

Installed on the back. Will be the most visible part to swimmers and can act as beacon. Aesthetics regarding color selection are crucial and should be made from self-supporting materials(such as sheet of rubber or plastic). Also, should be curved with no sharp edges to avoid user injury

3.Ventral Fin(Belly Fin)

Installed on the belly. While can be made similar to Gill Fin for aesthetics, it can also be made out of stiffer material and work as additional control surface should the tail fin not be big enough to provide enough control.

4.Tail Fin

The last section of the fish. Should be made from stiff materials since it's a control surface, but not too stiff to avoid injuries. Likewise, there should be no sharp edges. Currently, candidate material is black rubber sheet.