[clyde260]

A stuffing box is used to keep a majority of water coming through where the shaft enters the vessel below the water line. To your point they would still need a type of caulking between all the seams.

[Starboard]

A stuffing box is used to keep a majority of water coming through where the shaft enters the vessel below the water line. To your point they would still need a type of caulking between all the seams.

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Stuffing boxes are not only used for sealing the shaft; they are also used for rudder posts, some of which may be above the waterline. One of the things I was curious about was how they sealed the rudder which, even though it is above the waterline in the depiction, underway that can change with the load of the vessel and waves, especially in high following seas. The general point being that any through hull shaft/post needs to be sealed in some way.

BTW have you ever changed shaft packing while the boat was in the water? I don’t recommend doing this unless you really know what you’re doing. It can lead to some anxious moments. :)