If you want to make a career of working aboard ships or ocean-going vessels, you must have a license. To begin a sea-going career, get a Z-card, also known as a merchant mariner's document or merchant mariner's credential. Your entry level title as a beginner will be either wiper, ordinary seaman or steward.

Entry Level Licensing

Go to the Transportation Safety Administration website and follow the directions to apply for a transportation worker identification card, or TWIC. You must go to an enrollment center, "provide biographic information, identity documents, biometric information (fingerprints), sit for a digital photograph, and pay the established TWIC fee" to receive the card, according to the TSA.

Go to the National Maritime Center website's "application and forms" section. Download and print CG Form 719K/E Entry-Level Physical Examination Report, CG Form 719P Chemical Testing Report, and CG Form 719B Application.

Call a health care provider and schedule an appointment to complete CG Form 719K/E Entry-Level Physical Examination.

Call a Substance Abuse and Mental Health Service Administration (SAMHSA) approved facility and schedule a drug test or arrange for a medical facility to collect a urine sample and transport it to a SAMSHA lab. Ensure the paperwork documenting the drug test is completed.

Fill out the CG Form 719B Application for Merchant Mariner Credential. Arrange for an authorized representative to deliver the Merchant Mariner Oath.

Submit completed forms to the applicable Coast Guard Regional Exam Center (REC) as listed on the National Maritime Center website's "REC information" tab.