the water may also have come from the rudder post shaft.especially when porpoising up and down in any kind of sea way.I had that happen on many boats----especially while motoring.it has also come to mind that it may be a bad idea to store any outboard horizonally on its side---probably best to keep uprite at all times----as the rolling action of any boat may tend to allow any remaining seawater from a lower unit to find its way somewhere into the power head----rendering it useless when needed most.also all the inspection you can do at the hull/deck seem may result in not finding any leaks.however these boats are in fact flexible---after being under way for any length of time---be it a day or 40 days---these hulls will flex over time---resulting in a hull/deck deficit not seen before.