Over the years I have hired dozens of guides (and at one point did some myself) tipping should be based on the "experience" as a whole...If I find myself thinking that "this has been one of the best..."(a) boat and all equipment maintained and prepped properly (doesn't have to be new, but in good shape)everything is "ready to go"...shows pride and a "good" attitude...(b) his demeanor, does he strive to put you on fish...not himself...is he there to make sure a fish gets netted...does he give "tech tips"...like..."I like to use this or that because..."..."fish that a little slower/faster...etc. Not arrogantly, but friendly...Doeas he compliment you if you succeed and commiserate with you when you don't...Is he a genuine five star person?...(c) did you catch fish?...Catch a near trophy? Or catch a trophy?...If you find yourself saying; " I had a spectacular experience...", Then by all means...anywhere from 5-15%... in your case a crisp $10 or $20...at the end...when you have paid and packed up...then you can say..." had a spectacular time and this is something that you earned because I can tell you are not an ordinary guide..."
Everybody likes to feel good about themselves...the agreed upon price is "obligatory"...the tip isn't...it's a way of letting someone know they "did it right"...
When my now 20 yr old son, when he was about 10, went out with a guide who has now become a friend, he said to him; "my dad only tips a guide if he's really good...", as he handed Steve a quarter. Steve swears he still has that quarter...I think you get the message...
I have been on both sides