Fighting for Air — Marsha Mildon

Scuba instructor Jay Campbell takes her class of students out for their first open water dive. All goes well until a young Ethiopian man loses consciousness and drowns. An investigation shows his tank was fulled with carbon monoxide, and Jay is indicted. But Cal Meredith, in love with Jay and determined to prove her innocence, finds there are other suspects as well. This well-crafted mystery, set amidst the spectacular scenery of the Pacific Northwest, builds step by step, challenging the reader's sleuthing ability while adding Cal Meredith to the growing list of entertaining lesbian investigators.