current trailer tire tells all
this is easy. On the side of the tire, it will give you tire size and rim size. For example 205/75D14. That will give you the tire size and rim size. The only other information needed is the number of lugs or bolts that hold the tire onto the trailer. Then go to a trailer supplier, west marine, Northern Tool, etc... Northern Tool is a source and generally has tires on the rims and that too at West Marine. Stick with galvanized rims if going into the water allot.
