What does he want to fish for and how long are you in port? What time of year will you be there? Unless you're specifically talking about king salmon fishing in May and June, other ports may offer more variety and/or availability.
Whatever you do, DO NOT just hope to "pick something up" when you disembark. Fishing charters in SE Alaska are legally limited to no more than 6 anglers, and they book up fast. My charters are already about 85% spoken for for 2008, and some of our reservations have been in place for 2 or more years. (On average, the specific dates you want are likely to fill between 1 and 4 months prior to your charter.)
If you book via the ship, you'll be paying 30% to the cruise line, 50% to a broker, and the leftover scraps to the boat captain, owner and deckhand. Booking direct with a vendor will likely save you 10 or 20% (no ship commissions) and better yet, do you think you'll get a better tour from someone who's getting paid all of your money, or less than half of it?
In Ketchikan, I always recommend Ken Teune (pronounced Two-Knee). If he's booked, I'm sure he'll be happy to recommend another captain/boat for you.
Sitka, Juneau and Hoonah are also known for their fishing. Sitka and Hoonah are the better of all the ports for halibut fishing, and Juneau is known for it's large variety of fish available most of the year.
Hope this helps some... if you've got more info and specifics, post back and I'd be happy to help steer you to a great time!
Happy Alaska Travels!
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