Quite possibly one of the best investigation tools in the game right now. Not only does it have built-in skill boost and clue compression like Fingerprint Kit, but also come with three traits that already have a ton of support and synergies. Here are some of them I personally found interesting:

Item Synergies

• This is a very competitive investigation tool for Bob Jenkins even when pitted against Thieves' Kit or Lockpicks (1).
• Can be tutored with Backpack (and its upgrade).
• Throw it, bash someone over the head with it or crack boxes with it at +3. Unconventional Method + Nautical Charts can be overkill though, unless you're playing 3-player and want to get clues in multiples of 3 is more a novelty though, since you can usually achieve the net +2 boost through less destructive means (see below).
• Skill boost with Jury-Rig or Reliable. You can potentially get a lot of mileage out of the latter.

Tome Synergies

• It's an eligible target for The Raven Quill. Interwoven Ink is especially interesting as the on Nautical Charts is not limited by uses (compared to Grim Memoir which uses secrets for example).
• Double tap with Abigail Foreman.
• Full tutor with the Quill's Supernatural Record or Research Librarian. Also Whitton Greene.
• Throw it, this time to fight, at +3.
• +2 boost with Sleuth and Mystic Vane from the Quill.

Tool Synergies

• Wilson Richards can test at 5 at the very least and the charts is a valid target for Ad Hoc.
• Tool Belt, Tinker or Scientific Studies Grant to hold it. (Also Detective's Colt 1911s if Joe somehow got his hands on one of these)
• Fine Tuning to use it twice, though two discards a turn can be a little hard to keep up with.
• Pushed to the Limit to recur in a pinch if you dropped both in the discard and missed the Scavenging test to get one back.
• Nose to the Grindstone and Crafty for further +2 boosts.

Nautical Charts is perfectly serviceable as the Survivor's answer to Fingerprint Kit (0), but it has immense potential to get better and you'll be rewarded with a tool that can last you the entire campaign if you take the effort to build around it.

How does this card work with Scavenging? If I play it from my hand by discarding instead of exhausting, does the discard happen before I make the skill test and perform the action? And because it's in my discard pile, would I then be able to get it back with scavenging if I succeed by two or more?

It seems obvious but as no one has written a review yet ... Use the action on this card to discard Winging It: you gain 2 clues with Nautical Charts and then you can play Winging It from you discard to try to get 2 clues in a single action. If you play a solo deck, you can of course do this with the other Improvised events (Improvised Weapon and Impromptu Barrier).

And use Tool Belt to stack Nautical Charts, Hand Hook and Anchor Chain. Then you need a good card draw to get the events back.