Practice Run?
Another option is to make sure we all have the ability to sketch on the map on Roll 20. Then everyone can log on and draw out their ship routes when it is their turn. Use a battle thread here to declare attacks and post resolutions, they you can update the map and switch to the new (half) turn.
I might be able to log on for a synchronous session some times, but it could also go days before I'd be free and having an asynchronous options, although slower might actually go faster. :-)