Bowditch will be your only friend in the exam room.
Some things are difficult to learn from Bowditch, but others, including adding and subtracting time, and azimuths and amplitudes are very well explained and readily understandable. Personally, I prefer using the simple tables in Bowditch to solve amplitudes and azimuths instead of memorizing long formulae for the calculator that are prone to button-pushing errors. Even better if you can do it both ways to cross-check.
Bowditch is not the best place to learn the sailings, but once you know them its good to become familiar with the Bowditch method. You’ll have Bowditch to use in the exam room.