Objects

[blackbird36]

can you ride a 'Free Sailboat! (no modify) ?

[LoveAngeL Lyre]

Why not? Right click on it --> Sail

[Rolig Loon]

Hehehe... It kinda depends on whether the sailboat is meant to be ridden, and that has nothing to do with whether it's free.  To move, it will have to have a script in it that responds to SL's wind and your controls.  If that's there, sail away.

[Cabbage Acanthus]

That would depend entirely on the "sailboat" in question.  The best way to tell is to rez the sailboat somewhere where scripts are enabled and right click it to see if there is an option to ride it.  (or try sitting on it) if it is scripted so that it is a vehcile, you should know by then.

The object in question might be a simple decoration, a house built to resemble a boat, a skybox, a ridable vehcile... etc.  You will just have to rez it and take a look

Have fun!

[PeterCanessa Oh]

It will help you in Second Life if you realise there are millions of objects in the world, almost all created by residents, all completely different even if they have the same or similar names.  As such there isn't a "the ..." we would know about and it all depends on the specific object.

Having said that there are certainly free sailable boats at several of SL's yacht clubs so you can try them out.  Use search for 'sailing' or similar.