thanks for the input everyone.

So it seems to me there is no real good reason not to use them if a. properly secured b. snow isn't an issue and c. that ugly blue mono needs battens (and Dacron sails)

I have been using 1 or 2 very large tarps for years with no real issues, besides they degrade.

I just wanted to see if there were any reasons I hadn't thought of, or any "war stories" of death and explosions from tarps

Maybe 1 day I will get a machine and make some real covers.