My guess is the boat is using the Tides SureSeal, unless it has been swapped by a prior owner.
https://www.tidesmarine.com/sureseal/sure_vs_strong#:~:text=The%20StrongSeal%20has%20a%20stainless,removable%20Cap%20and%20Split%20Washer.
There should already be a spare seal on the shaft in a seal carrier.
When I change my seals I discard the active seal, move the spare to active and put a new into the spare location.
When I remove / replace the shafts / seals on my boat I use a seal protector to ensure the keyway does not damage the seal.
https://live.staticflickr.com/65535/50029500446_79694b4984_z.jpg
Each time I install a new seal I slightly shift the dripless seal carrier so it rides at a different place on the shaft, marking the hull tube so I know the locations used.
When I remove the shafts I use a step ladder to support the detached shaft for polishing. I use strips of sandpaper and a random back / forth and up / down movement to remove marks, such as from the prior shaft seal placement.
Also, long ago I used coarse / medium / fine lapping compound on the props and couplers, also cross lapping, to change from an original horrible contact pattern to a uniform contact, along w/ "impossible" to remove to now normal removal effort.
https://live.staticflickr.com/4654/40507538381_b0a121e3d3_c.jpg
https://live.staticflickr.com/4648/40507538291_b2ee90f6bb_c.jpg
https://live.staticflickr.com/4675/40465168122_4aaf8dffd9_c.jpg
Note that if the dripless seal carriers are replaced, the original parts had just a single port. When I changed mine I used parts w/ dual ports, with a crossover hose, so now I can safely operate, even with one engine disabled.
Don't forget to include an annual check on the dripless seal carrier. With the hose removed and the port blocked verify normal / sufficient water flow provided by the idling engine. With the engine off and the port unblocked verify unimpeded raw water intrusion backwards through the seal.