Just use common sense. Don't be excessive either way. Last year in Sitka, on a 3 day trip I tipped the Captain, whom also doubled as deck hand, $200, the deckhand $100. My 4 buddies tipped the same. On a side note; the fishing was so ridiculously hot, it was like a war zone. Those boy's earned every penny. Day fishing with a local guide around here, tips are about 20-25 bucks depending on previous nights celebrations.