If your present boat or truck has lettering on it already the removal is rather simple for vinyl. Most vinyl decals will peel right off if you are careful and work slowly. Just lift a corner of a letter with your fingernail and peel back slowly. Heating with a hair dryer or heat gun may be necessary to allow the vinyl to become more pliable when removing, especially in colder weather. If heating is necessary, work small areas for short periods of time. Excessive heating of vinyl will cause it to stretch and break off in small pieces. You may consider heating a small area, pulling off the vinyl and then continuing the same process over until completed. The vinyl will most likely leave some glue behind on the surface it is applied on. Once you remove all of the vinyl, the remaining glue residue can be removed with denatured alcohol and paper towels. Do not use cloth towels which retain the adhesive and will continue to smear it around the surface. When wiping the area with paper towels be sure to constantly fold and change the towel to trap removed glue. Dispose of paper towels frequently during this process. 
If your name is painted on the removal will be a little more difficult. Test and try these methods in a small, inconspicuous area to make sure that no harm will be done to the gelcoat, fiberglass or paint. We do not take responsibility for any damage that may be caused by any chemicals used to remove either vinyl or painted lettering. The following methods are only suggestions that have been tried and have been effective under various conditions. You must assume all responsibility for removal. The first method is to take some acetone and soak it into a sponge, (protective gloves and plenty of fresh air ventilation are necessary when using most of these products.) Next, hold the sponge onto the lettering for 5 to 10 seconds allowing the acetone to soften the painted letters. Remove the sponge from the contact area and scrape the existing lettering with a plastic squeegee, then rinse with water and wipe with a paper towel. 
The lettering should begin to come off. This process is very timely and requires patience. If the acetone does not work, oven cleaner, paint thinners or mineral spirits may have to be used in the same manner.