In response to the funny story from Douglas about military diving, here is a true story from the Royal Engineers Diving School when it was based on the Solent water at Southampton. Students were diving from the dive pontoon carrying out basic drills. The student concerned was a young soldier on his basic course. The drill was mask clearing underwater. The students were in lead boots on a shot line and tended by a lifeline. They would ascend to the surface fill the mask and show the full mask to the supervisor, then they would descend to 2/3 metres clear the mask and return to the surface by signalling on their lifeline. On the surface they would then show the clear
mask . If the mask wasn't fully cleared the diver would repeat the exercise until he had achieved a satisfactory mask clearance .
This particular diver seemed to be doing the right thing,{ inserting two fingers under the mask seal under the chin and by tilting his head back, blowing hard through his nose-thus blasting the water passed his fingers and out of the mask.] but he could never seem to achieve a fully cleared mask. Trying to give encouragement the supervisor reasoned that he was obviously doing the right thing as on three occasions he had surfaced with a 2/3 clear mask, then a half clear mask and then a 2/3 clear mask. When instructed to once again fill his mask and go down and empty it giving one last big effort,the diver indicated that he wanted to ascend up the pontoon ladder and say something.The water was ink black and stinky,{great training conditions !] He was pulled to the ladder and exited the water up to his knees. With his mask off he looked to the supervisor with pleading eyes and said," Don't send me back down to do the drill again 'Staff,' I just can't drink any more.!!.