Lens selection for Alaska

I went on an Alaskan cruise in July 2018 (Vancouver to Seward) and took all my lenses.  I figured I could leave the big camera bag on the ship, and take my small bag on excursions or on walks around the ship, using lenses that were selected to match anticipated activities.  My widest lens is the Fuji 27mm, any my longest is a Minolta 300mm.

The Alaskan coast is famously rainy.  Oddly, we had record-breaking dry/hot weather, and didn't see a drop of rain until getting off the ship in Seward.  (Ketchikan has a giant rain gauge sculpture with a salmon mounted 150 inches high to indicate the average annual rainfall.  It's wet!)  I don't have a single moisture resistant lens, and lucked out.  You have several, and I recommend you take them.

Wildlife shooting can vary a lot.  The 300mm was handy for some things, but your 18-135 would have covered most of it.  I don't have many zooms, so whale shots were done using 50mm, 100mm and 200mm primes, with occasional frantic swaps.   A zoom would have been much more handy.  And there can be unexpected opportunities; while on a small wood bridge at a national park, a black bear walked below, and I got close up shots using the 27mm.

If you're doing an inland passage cruise, the shoreline can be pretty close to the ship in spots, and your 12mm would be helpful where the wide end of your zoom lens isn't wide enough.

Have fun!