For whatever reason, boats leak. Some faster than others. Just a suggestion.
Take it and moor it for a few hrs, and check it for leaks. The shaft seal is probably the source of some leaks. Once you determine that it's leak rate is within your time budget, then you are probably ok. That is, it leaks a quart of water in xx hrs. Then go and check it again.
If you left it for 3 days straight, and then found a foot of water in the engine compartment, that would not be funny! But if you check it every day, you may be ok.
Maybe a cheap bilge pump, hooked to the batt, that has a float switch would be cheap insurance.
After this little vacation, rinse her out good.
I don't know everything, but I have seen outboard motors, with the lower unit rotted to pieces, from salt water!
Nate