Definition of "mariner"

From the ground, Colombo’s port does not look like much. Those entering it are greeted by wire fences, walls dating back to colonial times and security posts. For mariners leaving the port after lonely nights on the high seas, the delights of the B52 Night Club and Stallion Pub lie a stumble away.

2013 June 8, “The new masters and commanders”, in The Economist, volume 407, number 8839, page 52