Global interest has been caused by attempt to locate Oceangate’s Titan submarinewhich entered the water with a crew of five to explore the wreck of the Titanic but was lost an hour and 45 minutes into its dive.

In the past the submarine has made “trips” to the wreck of the Titanic, which the company has recorded and presents in videos hosted on its website.

The Titan is a five-person vessel that the company says was built “for field survey and inspection, research and data collection, film and media production, and deep hardware and software testing.”

Typically, each dive has a pilot, three guests and a guide. Once these people are inside the submarine, the hatch is bolted from the outside and must be opened again from the outside. The descent from the surface to the Titanic usually takes three hours, with the full submersion taking about eight hours.

Throughout the journey, the submarine emits a safety signal every 15 minutes which is monitored by the crew on the water. The vessel and surface crew can also communicate via short text messages.

Technology writer and reporter David Pogue, who took part in the 2022 mission for a CBS News show, said that all passengers boarding Titan sign a declaration that they know they are entering an “experimental” craft “that is not approved or certified by any regulatory body and may result in physical injury, disability, emotional distress or death.”