Player Character Downtime

There have been three mentions of this recently on the Ironcrown forums. How do you handle the time when the player characters are not adventuring? This is also part of the problem I have with sea voyages as I was writing about recently.

The discussions I mentioned involved playing an alchemist who by necessity requires great amounts of time to create magical items, characters that take to crafting or mining and simply healing time for fighters. In my case I was thinking of enforced inactivity while on a boat or ship.