Leaving on the Alaskan cruise tomorrow but HAVE to get off early in Ketchikan. Princess says that due to the "Passenger Services Act" it is illegal and can carry fines of up to $3,000/passenger. Per Wikipedia and the Customs & Border Control, this fine should only be $300. Is Princess employing scare tactics, or do they tack on additional fines? Are there any other penalties involved? I don't want to go on the cruise at all until I know all the details.

Perhaps you should call the Ketchikan Office of CBP and ask them. Princess may have a contract right to assess their own fees to cover their having to provide special services to you. The logistics involved, getting CBP to come to the pier, etc. They no doubt want to discourage this type of thing since it is indeed a violation of the law.

I doubt it would add up to $3000 per person. More likely is whoever you spoke with at Princess misread the fine.

No doubt this action is discouraged. We contacted Ketchikan CBP and they were very understanding, stating that this was not uncommon. Notifying us of the possible $300 fine and suggesting we contact the head of Passenger Services once onboard to inform them and complete any necessary paperwork.

I've printed out the Passenger Vessel Services Act they've cited from Wikipedia and it clearly states a fine of $300, but also says "in order to embark in a US port and desembark in a second US port, the cessel must visit a port outside of the USA". Since our first port will be Victoria, B.C., shouldn't this exempt us from this act?

Don't take Wikipedia as an authority on this (or anything). There is more to it. There are different rules for "nearby" foreign ports and distant foreign ports, lot of other stuff. I suggest you read this excellent article written by a friend of mine. It is from 1999 but still provides a great overview of the law and it's caveats.

Very informative. Thanks for your help!