Bublehead is a shortened version of bubblehead which is what Submariners (like myself) in the US Navy are called by the Surface Warfare types, i.e. the blokes that we liked to call “targets”. They thought it was a great put-down. Submariners are a crazy lot, so we started calling ourselves bubbleheads just to get their goats. In the early days of the net, IRC chat rooms only allowed a nickname 9 characters long, so I dropped the extra “b” and became Bublehead on all the forums. Hit me up for some crusty sea stories from the cold war, buy me a pint of my favorite, and I’ll spin a yarn for ya matey.