Please note that the PICTURE UPLOAD function is not working. The iBoats Forum Moderators are working with the system administration folks at the parent company to get the issue resolved. This happened about a year ago and here we are again. In the meantime you can post photos as links to a picture hosting site of your choice. We are sorry about the inconvenience and will advise when the issue is resolved. Thank you for your patience.
I would replace the gaskets on the vent and drain plugs first, before you go through the time and expense of resealing everything. If it still leaks after that, then you may also need prop shaft seals, as well the upper seal.
Try another change of oil in it and see if water still gets in. If it does, then I would go a little further with it and change the seals that haven't been changed yet.