Is this what you mean, Milly? It does look a bit frog-like but its fins are not how steve described them.

The links don't work for me at work or at home so I had to right click, do properties and copy and paste into the browser and then they worked.

Meanwhile: It did not look fish like. No fin on the top, fat and squat, had to look hard to see there was a tail(very short), and these silly little side fins that looked like deformed arms.

Looks like I have missed my chance of 15 minutes of world fame not getting a picture. Luckily I can blame it on the wife who walked off down the jetty with the camera to get out of the wind, while I waded through the water looking for the clam!

well the links worked for me. From what steve says idont think its a puffer, as he said it only moved about 3 inches, they normally move around if approached.
my thinking is possibly a redseawalkman or something like that as they are slightly froggy looking? and dont move much.
not sure if this link will work, but maybe, :
http://i1.treknature.com/photos/1189/img_8567a.jpg

403-forbidden on the last link unfortunately. But thanks.