Four military medals were among the items stolen from a man's bag as he swam in the sea in Bridlington.
The victim had left his bag on the beach, near to a hut on the south side, but when he returned his belongings had been taken.
The medals were:
* Northern Ireland Medal: Green and purple. Regiment number 25183263 on the side.
* Iraqi Medal: Black and red stripes. Regiment number 25183263 on the side.
* UN Medal: Navy blue.
* ACSM Medal: Green, purple, and orange.
A wallet, cash and clothes were also taken from the bag, between 9.45am and 11.30am on August 21.
Anyone with information is asked to call 101 quoting 16/90238/18.