Sorry, got this last week from the Alaska Ferry Company and thought I had posted it.
The official Alaska Marine Highway policy on fuel is as follows.
Small portable containers of fuel (6 gallons or less, and limited to 2 containers) are permitted on board AMHS vessels. Diesel tanks designed to fit in the back of a pick-up, or other small trucks, are allowed up to 119 gallons. Diesel fuel, in 55 gallon drums (not to exceed 119 gallons) are permitted per transport vehicle when in un-damaged and secure containers. They must be turned over to vessel personnel for proper storage while en route.
Looking at your link, you should be fine as long as the container is in good condition and the amount of total fuel carried does not exceed 119 gallons.