Repacking the stuffing box while the boat is in the water is fairly easy. The secret is to have some bicycle inner tube rubber handy. Also a tool to pick the old packing out. I use an old screwdriver that I've sharpened to a point and bent the tip a bit.
1. Back off the locking nut and then back the stuffing box off the shaft.
2. Wrap the inner tube rubber around the shaft and the shaft log and tie it
off. This'll stop the water from coming in.
3. Pick out all the old packing. Sometimes this is the hardest part of the
4. Cut a ring of packing and put it in the stuffing box. Cut another ring and put it on 180 degrees from the first one. (so the joints aren't in the same spot. repeat with a third ring. If you find it difficult to get the packing in, turn the stuffing box down the shaft log after each ring.
5. Take off the rubber and turn the box down. Tighten the lock nut.
6. Run the engine
the stuffing box. It should drip slightly, a drop or two per minute. If it doesn't drip and gets hot to the touch loosen the box a turn. Getting it just right is through trial and error.