We have been searching for a vessel to host an electronic tracking device. We have purchased the SubSafe product to be our host for a river science experiment along the Blackstone River in Massachusetts and Rhode Island. Our river is 45 miles long. We are placing our pink SubSafe into the river in Worcester MA next week to track how long it will take a drop of water to reach Narragansett Bay in Pawtucket RI, 45 miles to the south. Wish us luck! We are hoping that children will join us on line and watch SubSafe carry its cargo south. If it works well we will then recharge the vessel and begin a bay voyage from Pawtucket RI to Newport RI through Narragansett Bay. Wish us luck!