Will this work with rubber underwater?

Hey there! Our customers have had success with applications beyond those for which the product was intended. We always recommend testing the product in a small area before completing a project. For more information regarding the product and its intended uses, please visit this link: https://flexsealproducts.com/products/flex-seal If you have any other questions or need project-specific help, send us an email at humans@flexsealproducts.com or a DM on socials. We're here to help!