They need to be in pen, and if something needs "corrected", then a single line is put through the section, such that the section can still be seen.
log
log fog
That's the ship's log.
Ships Deck and Engineering logs.
It is a log that merchant seaman use to log their discharges from ships so they are not found to have abandoned a ship illegally.
a ships log -apex
It's referred to as a "Ship's Log."
The detailed and daily records of a ships' progress AND everything else (weather, oil-levels, water-levels, tidyness, tenure, etc) going on onboard the ship is being added almost as it happens onboard into the log book by both Captain and Chief Mate. If the ship has a Chief Engineer, he has a similar book for the engine room.
Snipers are the only ones who do this, and they simply annotate it with a pen (or pencil) and paper.
AIS tracks live ships by Satellite. You can learn more about the AIS and their methods from the official AISlive website. If you are already a member, you can log in to start tracking ships.
Superstitions surrounding ships probably began the very first time a human launched onto water clinging to a floating log.
Something like a pencil or log, because it was cut off from something bigger.