The Ocean Troop Transport (OTT), also known as the S-TRN, was a submersible transport used by the Trade Federation to transport B1-Series battle droids over and under water.
The OTT had a slow top speed and often had a bad habit of sinking. It performed more reliably as an aquatic surface repulsorcraft. Two versions of the craft existed, one armed and one unarmed. The armed version was described as a battleship.
The OTT was used to deliver battle droids for assaults against the cities of Spinnaker and Theed. Possibly a modified MTT, the OTT was also used at the Battle of Naboo to invade the underwater Gungan cities.
These vehicles were referred to simply as "submersible tanks" in Secrets of Naboo. Star Wars: Galactic Battlegrounds used the name "S-TRN," apparently standing for "Submersible TRaNsport." The New Essential Guide to Droids used the name "OTT," standing for "Ocean Troop Transport."
Leland Chee, when asked about the OTT, confirmed that it was the same as the S-TRN from Galactic Battlegrounds, although he stated that it was more comparable to the AAT than the MTT, despite the visual similarities.
- Secrets of Naboo
- The New Essential Guide to Droids
- The Complete Star Wars Encyclopedia