Deepdive might be in Michael Bay’s Transformers: The Last Knight.
A redditor in the UK where Transformers: The Last Knight is filming spoke with Anthony Hopkins and Mark Wahlberg where the actors teased “something” will be happening with the HMS Alliance that is on display at the submarine Museum there.
In Transformers lore, Deepdive transforms into a submarine and is a member of the Mini-Con team. Mark Walberg also confirmed Mini-Dinobots for Transformers: The Last Knight, so I suppose there is a connection.
Deedive is a member of the Mini-Bots along with Overcast (a seapane) and Longarm (construction vehicle).
Other possibilities for the Transformers: The Last Knight submarine could include Astro-Sinker, Seawave, or Diveplane.
“Transformers: The Last Knight” has a June 23, 2017 release directed by Michael Bay starring Mark Wahlberg, Josh Duhamel, Stephen Merchant, Isabela Moner, Jean Dujardin, Jerrod Carmichael, Allen Phoenix, Lauren Haddock, Stanley Tucci, John Goodman, Ken Watanabe, Tyrese Gibson, Anthony Hopkins, with Peter Cullen returning as the voice of Optimus Prime.