At least for US Flagged vessels over 12 meters in length, there is a requirement to have a copy of the Col Regs aboard. Seems a good idea in any event, unless you have them memorized in all their details—which is unlikely.
In the same vane, a copy of “Chart 1” is very handy if you will be using paper
charts at all. “What is that little purple squiggle about?”
A long term almanac, instructions on how to use it, and a
sextant could be really important if you lose your
navigation video toys from a
lightning strike in the middle of the ocean.