Can I use the name of a small sailboat?

It can be used.

Skyboat can be used as a name. Although "Sailboat" is a type of "Ship", in the current context, "Sailboat" is more likely to be understood as a name rather than the name of an object. At the same time, using "Sailboat" as a name does not violate public order, good customs and language habits, so it can be used.