Not a luxury item at all, but procure and bring a dozen ( or so) butterfly wound closures to elevate your group's own first-aid capability.

If fishing is on the entertainment agenda, be sure to have a "leatherman" type tool or a pair of wire-cutters stout enough to deal with your worst possible hook/ human accident.

Sorry to harsh the mellow anticipation, but it takes only moments for stuff to happen, and the more easily you can deal on your own terms, the better the days go.