You mentioned that he likes fishing so he might like something he can use for that, but he also might like something he can carry with him (which I assume means a folding pocketknife). As suggested, Buck Knives has many great options as does the knifemaker's forum here.
But, if he wants something more modern then Spyderco is where to look. These models are particularly suited for use around water, as the steel is virtually rust-proof (while also being good steel for edge retention):
- Spyderco Pacific Salt-2 (green-frn-lc200n-blade-fully-serrated)
- Spyderco Para-3 Salt Lightweight (yellow-frn-magnacut-blade)
- Spyderco Manix-2 Salt Lightweigh (yellow-frn-magnacut-blade)
Several vendors offer laser engraving, one of which is DLT Trading.
Don't let the bright handles deter you. These are great knives and there is an easy method that many (including myself) use to dye these handles into whatever color they want using RIT brand dyes for synthetic materials. It could be a fun project where you dye the handles to match his college's colors, adding a personal touch to the gift.
Whatever you choose, you'll definitely be known as the Cool Aunt!
*Edit: I removed links, thought that DLT Trading was a contributing dealer.