Lock Ness - Escape Envelope

A renowned Cryptozoologist has entrusted you with his discovery of a secret cave beneath Loch Ness. But to keep the coordinates safe, he has disguised them within a series of documents!

Now in his eagerness, he has descended into the Loch in his personal bathysphere with only an hour's worth of oxygen!

Can you decipher the code and find him before he runs out of air?