According to the Houston Chronicle, merchant marines earned a base pay of $18.36 per hour in 2013. Even though they earn an hourly rate, they are paid per 24-hour period, so overtime earnings are common.
Merchant marines can earn much more depending on their job title. Each position earns a base rate plus overtime while on duty. Many in this profession work a certain number of days on the ship at sea and then have one to two weeks at home, which is called shore leave.
As a merchant marine climbs up the ranks, he has the potential to earn between $170 and $800 per day.