In ancient times, ships would often be at sea for extended periods of time. During this time, I'm assuming they must have done some form of cooking, otherwise they would have just eaten cold, pre-prepared food for the whole time between stops at ports.
As these ships were wooden and possibly covered with tar for waterproofing, how would they have cooked without risking a fire in the galley?
From the research I've done so far, ships a couple hundred years ago would have had a barrel/bin filled with sand on which they lit their fires:
Sailing ship provisions - Food and drink
I can't find any references for ships further back in history (this is possibly because I'm not sure how/what to search for).
If possible, I'm mostly interested in Egyptian and Middle Eastern ships.