Just thought I'd pass along some information I discovered while build my hybrid kayak. I have a nice Dewalt stapler but still found myself with inconsistent tacks. In my woodworking arsenal I have a Porter Cable Crown Stapler. Using a 18 guage, 1/4 inch staple and setting the regulator to 40 psi and the stapler to the minimum depth of bury, I have great success with perfect accuracy, minimum effort, and a solid tack with plenty hanging out to make removal easy. Every few tacks you will get a missfire due to using it below rated psi however, you will find it well worth it. 

Mike