This volume contains recommended quantities indications and dosing for 55 medicines listed in the International Medical Guide for Ships 3rd edition. The quantities are based on three types of ships:

• ocean-going ships with crews of 25–40 and no doctor (Category A)
• coastal ships with crews of up to 25 that travel no more than 24 hours from a port of call (Category B)
• small boats and private craft with crews of 15 or less and usually travelling no more than a few hours from a port of call (Category C)