Murdered by Nature by Roderic Jeffries

Optimism, as Inspector Alvarez knows, is the road to calamity . . .  - Inspector Alvarez is in a good mood, for once. The sun is shining, he has enjoyed a morning nap at his desk, and his irascible boss - Superior Chief Salas - is on holiday. But his new-found optimism soon leads to disaster. In no time at all, Alvarez is mired down by a seemingly impossible task - identifying a man drowned in the bay, who it quickly transpires may not have been drowned at all .