Just finished fishing a week in Costa Rica catching Sailfish, Blue Marlin, Striped Marlin, and even a Shortbill Spearfish. Long story short, great trip on my buddies boat, once in a lifetime opportunity for myself and my son. On Saturday my son caught a Sailfish, Striped Marlin, and Shortbill Spearfish creating a single day Slam event. The Captain, deck hands, and everyone on the boat was super excited. These catches were a team event but ultimately they all credited my son with the slam. He also reeled in a blue marlin on a different day.

As requested by the owner, tips weren't to be given as these guys are fulltime on his payroll. But I would like to do something for them. Needing some ideas from people who are more experienced and willing to spend several hundred dollars. I would like for it to be useful if possible. Thought about customizing face shields, shirts, but they seem to have plenty of these items. Looking for suggestions.

Deckhands are often anglers themselves and I have found they are always happy to get fishing tackle, especially trolling lure, hooks (Grander Marlin Hooks are $20 each), leader, etc.

Or you could just send them my book, The Art of Fishing for Records. It has a priceless value of information lol.