Maybe you could take a "land/sea" cruise. The cruise ships follow the inside passage most of the time I believe, making ocean travel fairly easy. It's beautiful trip and very relaxing not to mention the scenery. We went about 6 years ago after the cruise we took the train (3 days) up to Fairbanks and saw a lot of the interior including Denali.
Since then we've been to Alaska twice, in March for Aurora Borealis viewing and are seriously considering a l-o-n-g RV trip the next time to Alaska.
It's an absolutely beautiful state!! I would encourage you to research remedies for your motion sickness as there are effective medicines available which might make your dream trip come true!
This sort of Alaska trip could be done in two weeks.
Good Luck
Dan