We always like to have our own car so we can come and go when we are ready.
Nevis is pretty much just a circle of road around the island so you won't have a problem with getting lost.
I hesitate to mention that we really enjoyed driving around in a mini-moke. I am not sure if they are any longer available.
However taxis are plentiful and the drivers are quite friendly. This is a good alternative especially when it is raining.
There are several ways to get to Nevis from St.Kitts.
Our hotel helped us make arrangements to fly in on a chartered jet.
It is a very short flight therefore economical.