Each one of the boxes has at least one rock, lol bolder that I could carry then added rocks in addition to that, I almost thought about take a bag of 40lb sakete and put on each so when it ever decay a cave type structure would be left.
The boards are not air tight top and bottoms made from old cedar deck boards that I got a few years ago even have a few hole in them so air should not be a problem.
Not going to put dock in, out of money anyway.
