You might consider just running a sander over the area, especially if there are any chips, and not try to strip it all the way to metal. Start with 100 grit if there are deeper chips or rough patches, then move up to 220 grit. Existing paint that is stuck well is a great primer!
Now this is very important... If using spray paint, make it VERY light, just a "dust coat" that doesn't cover completely. Do that several times, allowing it to dry well between coats, until covered. Let it dry for a full day or longer. You want all the solvents out of it before doing the "real" paint.
The reason for this is because spray paint has a lot of solvents in it, and those solvents can get under the existing paint and make it lift and separate from the hull. Doing the light dust coats allows the solvents to evaporate before affecting the surface. Once you have it sealed and dried solid, you can paint as normal.
I have done a lot of painting, and I usually never strip it all the way down, unless the original paint is absolutely horrible, and not bonded well. If it's tight in most places, I sand it smooth, wipe down with acetone, do a light seal coat, and then paint. They make an acrylic/vinyl sealer for just that purpose, but I tend to use any leftover paint I have laying around.
I hope this helps.