I'll post this here.
I have come up with a great idea for an observing chair that is water resistant, vairible height and relatively cheap.
A bar stool from The Reject Shop for $59.00. it is a heavy duty gas lift stool that gives a good height range for most applications. I have bought one and it takes my weight quite well (I'm not exactly petite!

) Check it out for yourselves, its a great tool for those with a handyman handicap