PMY - Power&Motoryacht

Step 12: Tighten either spud, or gland-type stuffing boxes just beyond hand tight while out of the water, and lock the nuts together.

Conclusion: Check the stuffing box in the water while still in the travel lift slings, but run the boat at cruise RPM for at least ten minutes before final tightening. Once back at the dock, Gaston likes to see at least one visible drip of water every ten seconds. With correct engine alignment and straight shafts, a stuffing box should drip steadily while underway and be at least perceivably damp after the boat sits overnight.

Most in-water emergencies can be solved by adding one ring of packing to the three worn rings already in the stuffing box. Be sure to repack it completely at the next scheduled haul-out. The water that comes in while adding that ring is disconcerting but manageable—especially if you know what to expect after repacking the stuffing box at least once in the boatyard.