What is the name of the product used to seal the seams of a plywood floor on pontoon boats?

The previous sealant seemed like a rubber product, something like we used to see in the seems of city sidewalks. Can anyone help?|||The sealant as you call it, is a joining compound that is epoxy resin that has MEK mixed in it to make it flexible. You can find what you need in regards to material and process application at this website: http://www.epoxyproducts.com/flex.html|||a quality indoor/outdoor carpet glue will work very well and it's inexpensive.