I'm looking for a fish storage bag suggestion for my Wilderness Systems Radar 115. Would be used for saltwater fishing.

So, this is a great question. I had to look on Amazon for minimum 48" bag. I will get back to this with the one I have. Im sure you can get some real good expensive ones but I think mine was like $80 had clips and I just added pad eyes around my rear tankwell so it could just clip in. It has an inner bag made of some kind of rubber or plastic, then an outer insulated bag. I got some silver bubble wrap stuff (in the insulation dept) and layered it between bags. I could keep drinks in there too. If you get too small a bag the lid has to stay open and that melts all your ice fast.

Location you put the bag obviously matters a great deal. If you put it in front, have a good day then the surf coming back in will tax you by finding just the right sand bar to bury the bow of your kayak in to.

I use a very large IKEA tarp material bag.
IKEA used to hand them out for free when they first opened, but my wife says they are just a few dollars now.

Thanks for the excellent thoughts and suggestions. Will go with the Ikea tarp bag for the short term.

Edit: went back to YouTube and did a different worded search and found the Magellan Outdoor Fish Bag. It was what I have been looking for with several features that had not occurred to me. Got the last one at my local Academy store for $50. Have already put it on my Radar kayak. Hopefully, will be loading it with fish this coming week at Surfside Beach. I'm camping there for several days to kayak fish, as well as doing some surf fishing.