Mikrosh

A hot air balloon could be awesome. It could be rudimentary where you need to use a lot of fuel(wood or coal) to start it up like for example 1 stack of coal, and only have "room" for half a stack. Navigate a few miles in one direction bassed on the wind patterns in that day(it could even be N, E, W, S randomly each day) and match the direction of the clouds so you know if you should set sail or not. Once you touch ground, you need to set base for a few days to be able to gather enough coal to move it again and wait for the proper wind. So it wouldn't be overpowered but it would be a great tool for exploration.