we were at the san juan in a beautiful cove on the north side, sitting on the back of the houseboat I was bumped by someone coming off the roof and hit my wife, there go her prescription sunglasses..... her only pair and boy was she pissed. SOOOOO we got inventive, the glasses were in about 20ft of water, we got two big rocks, about the size of feet, I found a good sized bucket, we had our 12 volt inflatable pump and a 25' water hose. it was a good afternoon to realize that the pump couldn't keep enough air pressure in the bucket to keep your head dry at 20' (1 3/4 atmospheres) and those rocks tied to your feet took you to the bottom quick, but we got the glasses.