Camera Bag for Beach

I need some suggestions for a camera bag to use on a beach vacation. I am going on my annual trip to Bermuda, and I will be staying at a hotel on the beach. I am bringing my D90 with the Tamron 18-270 lens. Each summer, I go through this same dilemma of deciding on the safest and most convenient way to protect and carry the camera as I walk along the beach throughout the day. I'd like something light and comfortable that will stay secure as I walk along the shore in my bathing suit. I have so many camera bags, but they are bigger and bulkier than what I want to use.

Perhaps someone on this forum has an ingenious idea or can speak from experience in a similar situation. Thanks in advance!
Marie