Propane low pressure regulators are factory set at 3 PSI. if you can blow 100 times more PSI than that, id have to say you have been practicing.Blow through a straw and you will create 100 times more pressure that is coming through the regulator, very low pressure system. It stinks to holy heaven, I can't imagine how anyone could miss a leak. One last note just because you get a leak doesn't mean your boat will blow up. You have to be an extra special type of moron to blow your boat up with propane.
Also someone mentioned that he/she only opens the valve 1/2 turn. Propane valves are double sealing valves and as such need to be all the way open or all the way closed or they can leak past the stem packing. How many super smart propane users knew that.