The Detroit River's international waters stretch out for miles in either direction, winding along the Detroit skyline and kissing the Canadian border. As ships snake their way through the current, they pass lighthouses on small green islands, bridges stretched across overhead, and workers milling about on the riverside docks. Building on 20 years of boating, the captains of the Diamond Jack, Diamond Belle, and Diamond Queen let passengers take in these sights to the tune of guided narration as their ships' white and sea-foam green hulls slice through the water. The three ships have proven impervious to squalls and Poseidon's road-construction crews since their maiden voyages in the mid- to late 1950s, and safely gather up to 250 passengers on their panoramic upper decks or in protected lower cabins. Today, passengers on these storied steel decks can sip beer, wine, and soft drinks or nibble on snacks from an on-board snack bar during tours. Captains also pilot each ship on private group excursions, as well as school field trips past the river's ships, yacht clubs, parks, and docks.