Charter tipping etiquette: To tip or not to tip?

Charter tipping etiquette: To tip or not to tip?

A debate that comes up sometimes between some friends on tipping a charter; I'd appreciate your feedback:
1. How much to tip? What is an average tip? 10% min standard being 15 to 20%
2. Who to tip? - If there is more than 1 mate do you give them each an equal tip or give it to the captain to divide as he sees fit? I would always tip the Capt to split up, or tell him "this is for the crew"
3. Do you tip a captain when there is no mate (small boat)?YES
4. Do you tip even if you catch nothing, especially if you feel that the captain or crew didn't try their best? This is touchy.. To one person not doing the best can be one thing.. I would say, if you did not get the service you had in the past or was expecting, then tip what you think will get them to understand.
5. Should you tip for the charter and again for cleaning fish? Depends of if the boat or a cleaning service does the job, if  it is not part of the boat, then yes.
6. Is there a typical per fish cleaning tip? No it should be based on total cost
7. Do you tip if the boat insists on keeping whatever fish you don't want (rather than allow release?) This is a regional matter and you should understand this before going on the trip. 
8. Is tipping with fish acceptable (instead of cash), or is cash expected too? This too is a regional matter, depending on the laws on whether the fish can be sold. 
9. Should you tip in countries where tipping in general is not the custom? Check before going out and ask what is standard for that area, in some cases it is included in the trip cost. 

Always ask around as to what is standard if your not sure and always check with what is allowed. US West coast fishing (Ca.), sport-fish cannot be sold.