Calling, Messaging and Voicemail Solution, Specially Designed for the Crew. MTN Communications (MTN) announces the general availability of the first calling app for maritime crew. MTN OceanPhone Mobile leverages the Wi-Fi infrastructure on vessels, as well as the MTN network, for calling and messaging. The app runs independently of other subscribed services. MTN OceanPhone Mobile, an extension of MTN’s OceanPhone calling solution for crew, makes it possible for the crew to stay in touch using their own smartphones and tablets.