One of the first things a new boat owner must do before they go on their first ride is to apply their new vinyl registration numbers. Now I know the new boat owners may think it's more important to put their vinyl lettering on their new boat for their name and port, but your vinyl registration numbers are an equivalent to your license plate on your car. So, if you don't have them on, you could be fined by your local police and coastguard. A couple of pointers on those vinyl registration numbers are;
For example, if you have a dark colored boat, then your vinyl registration numbers/letters should be a light color. However, if your boat is white or light colored, the vinyl numbers and letters should be dark colored. If you use dark vinyl letters on a dark colored boat, they will be hard to read and you could be fined as a result.
Going back to my first point, if you have to remove any vinyl numbers or letters(whether it be registration numbers or just the name of the boat), the best thing to use is a hair dryer. Use the hair dryer or heat gun over vinyl
(move back and forth) after a few seconds you should be able to start peeling the vinyl off. Then after the vinyl is off, clean the surface with a cleaner such as Windex. There might be something after you take the old vinyl registration numbers and letters off. If it is not sticky or a film it is what's known in the vinyl lettering world as "ghosting". There is nothing you can do about this aside from painting the boat. However, your new vinyl letters and numbers should cover most of this.
So get those new vinyl registration numbers on your boat and get sailing or motoring!