There should have been a ROV accompanying the Titan+Sub, just incase anything were to go wrong.
https://nypost.com/2023/06/25/teen-on-titan-sub-brought-rubiks-cube-to-break-world-record/
3 other submersibles visiting Titanic almost suffered the same fate as Titan https://www.cbc.ca/news/canada/newfoundland-labrador/subs-titanic-expeditions-1.6887824
