what sea is between Greece and Turkey

That would be the Aegean Sea. I've sailed through those waters more times than I can count, and honestly, it's one of my favorite stretches to navigate. The way the islands are scattered between the two coasts makes for some pretty interesting routes, though you really have to keep an eye on the winds when you're crossing through there.

It's definitely a busy area with all the ferries and cargo ships moving back and forth. If you ever get the chance to be on the water around there during the summer, the views are absolutely unreal. Just make sure you've got your charts ready because those coves and passages can get a bit tricky if you aren't paying attention.