The author is a diver and amateur marine archaeologist who directed the recovery of artifacts from his prime discovery -- the remains of the Spanish galleass Girona from ""Port na Spaniagh"" (or ""Giant's Causeway"") off the southwestern tip of Ireland. Claiming the first excavation of an Armada shipwreck since the 18th century, he found cannons, coins and seals, ingots, jewels, plate and assorted ship's gear. Stenuit's an enthusiastic researcher and before chronicling his underwater adventures he retells the Armada story particularly through the letters of the commander (The Duke of Medina Sidonia) to King Phillip which warned constantly of failure via ""inferior forces, inexperienced crews, officers of which not one...is up to his position."" But it was wind, weather and the fatal missed rendezvous which sealed the doom of the forest of masts. Mr. Stenuit writes with unabashed excitement about his finds -- whether in the stacks or fathoms down -- while tracing the fortunes of the scattered ships. A stimulating historical addendum, but more a siren call for prospective divers.