Fill in the membership service book from the time you start to work in navigation. The Crew Service Book is an important qualification document for seafarers, and the corresponding sailing experience needs to be recorded when filling it out. According to people's livelihood Com, the qualifications of the crew service book were recorded from the time they started sailing. This means that when you fill in the qualifications, you should start from the date when you first took up a sailor or related position. If it is the first time for you to fill in the crew service book, you can write down the date when you obtained the sailing permit or went aboard to work.