USS Grenadier SS210

My father was a crewmember of the Grenadier when it was lost. I have an old map (1942) with possible clues to location. They were going to try and get near the "Pilgrim" Islands. There are several islands SW of Phuket and I believe one is the Pilgrim Island. They scuttled in about 300'. The map I have has depths listed in fathoms and the areas marked are the approximate depth. I have talked to several crewmembers and some of them talked about that day. It was my father's birthday when they were attacked.