The Marina isn't remembered for much of anything in particular from its 14 years in existence.
It opened in 1975, just north of Tropicana Avenue on the east side of the Strip at 3805 Las Vegas Blvd. S. It started out with 870 rooms, 156 of which were in a motel building already occupying the property; the 14-story tower was built in front of the motel. The low-rise motel was subsequently knocked down and replaced with a parking lot, leaving the Marina with 714 rooms. (It was one of the few Las Vegas hotel-casinos ever to shrink in size.)
When it opened, it had the 24-hour Fred Harvey's coffee shop; Shipwreck Kelly's Galley, a steak-and-seafood restaurant; Shipwreck Kelly's Nautical Bar and entertainment lounge; and Fred Harvey Southwest Trading Post, which sold Indian jewelry and crafts. The Marina Showroom had a dinner show for $9.95.
At some point in the early 1980s, Kelly's was renamed the Port of Call restaurant; it had the same nautical décor.
The Marina was one of the four casinos owned by Parvin-Dohrmann and Recrion corporations in the mid-1970s that were sold to Argent Corp., during the shortlived Allen Glick/Lefty Rosenthal era in Las Vegas. In 1989, the Marina was sold to Kirk Kerkorian, who changed its name to the MGM Marina and ran it for another year or so.
The Marina closed on Nov. 30, 1990, at the start of construction of the MGM Grand. Kerkorian determined that the Marina tower was of sound construction, so instead of knocking it down, he incorporated it into the design of his 5,000-room resort. Today, the original Marina tower is the one that points west and is known as the West Wing of the MGM Grand.
Many thanks to Deanna at www.lvstriphistory.com for her help with some of the facts for this answer, and for providing us with the pics.