We took 11 dollars worth of materials. We took epoxy and stuck a Big bison tube to a rock and let it dry. Then inside we left it holding a bison tube, holding centrifuge tube, holding a small nano for 4 layers of redundancy keeping the log book dry for our underwater cache GC8948E sitting at the bottom of the James River in Richmond, Virginia. We then painted the rock and set it at the bottom of the river. So far this design has managed to stay dry for a month not even the first container has been breached. Message me with questions.