I saw your other post on oar height which listed boat specs, with 19" tubes an 18" drybox is going to be way up there (top of tubes to top of floor will be about 12"), especially with a tractor seat. I had a 13' version of that boat and my cooler was about 19" high and with 8" NRS towers while sitting on the cooler I could barely row (oars at knee level to get them out of the water). So you would either need really tall towers or really short oars. My drybox on that rig was 15" tall if I recall and with a tractor seat bolted to plywood and strapped to the drybox it was OK but I preferred being a bit lower so on overnighters I took off the tractor seat and sat on padded plywood (probably 2" lower than when on tractor seat and it was a perfect rowing height). This was all with 9' oars.
Yesterday's gone on down the river and you can't get it back. - Agustus McCrae