As a general rule, I would not normally tip a professional.
There are exceptions. If something "unexpected occurred" and the response was "very well done" ( especially if the result was success ) then a nice Thank You is appropriate.
Examples include your lawyer winning a case that did not have a snowball's chance in heck of winning, an MD who, by thinking fast, save my life ( or that of a loved one ), or, as in this case, a Captain who delivered service well above the expected ( and/or required ) level. For "straight up professional service" they get a handshake, my personal thanks, and possibly a referral ( or two, three etc )
-eidt-
What to tip? Sometimes cash is appropriate, but more often a "very nice bottle of their favorite adult beverage", or perhaps a GC to, say a mail-order top-of-the-line prime steak outlet ( Omaha Steaks ). It depends. If you are truly thankful of the exceptional performance, put a few minutes of thought into it and make it special ( and individualized. ie: for HOGAN, tickets to a Yankee game...

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