"What happens to a full water can when it falls into the water?" was a question that came up. It will probably sink. Val then chimed in, "I've read that some folks purposefully don't fill their water cans to the top thereby leaving some space at the top of the cans so that they will float." Brilliant! Such a simple solution.
My maximize space mentality would certainly have filled each Jerrycan full of water, but the "work smart" part of my brain sees that leaving some space at the top of the can will provide a certain amount of insurance just in case a water can falls overboard. There is also the added benefit of a lighter can. My back will like that!
Water cans going overboard isn't just a concern when ferrying them via dinghy, but also as they sit on the boat in the cockpit. One good rouge wave could send one overboard, and it would be nice to have the option of retrieving it if the conditions allow.
Lots of little details out there, and the mental scenario exercises really help flesh them out.