A British fishing trawler caught the surprise of a lifetime in its nets, setting off a chain of events that ended with a massive explosion in the waters off Scotland. The catch: a wartime German mine at least 80 years old.

After a brief investigation, Royal Navy divers lowered the mine back into the water and blew it up, sending a tower of water into the sky.

The fishing trawler, assigned to Scotland’s fisheries management agency, snared the mine. According to the BBC, the trawler’s crew alerted local authorities. Maritime Executive picks up the story, explaining:

The trawler’s seven crew were evacuated by the RNLI Troon Lifeboat and Rothesay Coastguard Rescue Team, and the vessel was sailed to Ettrick Bay on the Isle of Bute to meet with EOD divers. They declared the mine, which still contained around 750 pounds of explosives, to be in pristine condition and decided a controlled detonation at sea was the best solution.

The @RoyalNavy bomb disposal team from Northern Diving Group were in action today at #Ettrick Bay, Isle of #Bute, disposing of a German WW2 mine. The ordnance was trawled in the Firth of #Clyde & still contained 350kg of explosives. That equals a pretty Big Bang!