The Madame Blanc Mysteries S03E01 - Ocean

Judith and Jeremy have loaned their boat to a group of marine biologists. While diving, Gary, one of the experts, discovers a rare gold coin and pockets it, but tragedy soon strikes when he goes into cardiac arrest in the water. Caron shows Jean the treasure and enlists her help to investigate the death. Was this team of scientists really combing the seabed for minerals or could something else have led to Gary's demise?