The raft does, however, qualify as a vessel which means that I am required to have Coast Guard approved life jackets for everyone on the raft as well as a signaling device (a whistle) and a light should I spend the night on the water so that other boats can see me. One quick trip to a box store and all three criteria were met.
In finding out the legal requirements for the raft, I also found out that there may be restrictions on using barrels that once contained DMSO. I've also sent an email to the Washington State Ecology Department to see if they can help figure that out.
We also went to a nearby cedar factory outlet and loaded up on 6' planks that worked nicely as deck boards for the raft. On a side note, the outlet closes at 1pm on Saturday, and we arrived at 1:30pm not knowing that they had already shut down, but the guys were awesome about it and they let us load up anyway. A special thanks to Cedar Factory Outlet in Battle Ground, WA!
By way of construction, all I have left to do is to add in the other two 6' lengths of PVC so that I can lift both sides of the tarp, attach the fish net to the underside for carrying the cargo, and slap together the mini-hammocks that will fill in the open middle sections so that lads can hang out while floating on the water.