Which ship are you on? I tried using 3UK's pay as you go sim. It has coverage in Alaska, and 71 other countries with its roaming, but not including Canada.
$12/10GB a month.
I also tried US mobile(verizon sim). It has coverage in Sitka, Juneau, Ketchikan amd Skagway but not in Canada.
And since my phone supports eSim, I got myself an eSim. $40, 35GB good for 1 year. Works in USA, Canada and New Zealand.