General Manager
Coastal Transport Limited
22 Germain Street
Saint John NB E2L 4S6
Subject: Marine Transportation Safety Information Letter 02/24 (occurrence M24A0188)
Deer Island Princess II bottom contact
On 06 June 2024, the ferry Deer Island Princess II, with 25 people on board, made bottom contact while crossing between Letete, New Brunswick, and Butler Point, New Brunswick. One of the vessel’s 2 Z-drive thruster units was damaged. There were no injuries or pollution reported.
In accordance with the TSB Occurrence Classification Policy, the circumstances of this occurrence were assessed, and the occurrence was classified as a class 5 occurrence. Consequently, TSB activity was limited to the collection of data, which has been recorded for safety analysis, statistical reporting, and archival purposes. The following paragraphs contain safety-related information derived during the assessment of this occurrence.
The route used by the Deer Island Princess II to cross between Letete and Butler Point involves transiting through a narrow channel between Macs Island and Jameson Island. The water depths in the channel fluctuate with the tide, with the maximum chart datum in the channel being 2.2 m. The Deer Island Princess II has a draft of 1.5 m, meaning that the vessel’s under-keel clearance is less than 1 m when low tide is less than 0.3 m.
On the Deer Island Princess II, both Z-drive thruster units are used to propel the vessel, and steering is done continuously throughout the crossings to counteract the effects of crosswind and current. At the same time, collision avoidance, a radar watch, and navigation duties are also carried out.
On the occurrence voyage, the Deer Island Princess II departed Letete at 0630 and was navigating in restricted visibility of less than 100 m. Low tide was at 0633, with a height of 0.1 m, and the water level in the channel was very low. The ferry encountered vessel traffic on approach to the channel and, after altering to pass the other ferry on this route (the Abnaki II), a new target appeared on the radar. Both the master and mate looked for the target visually through the bridge windows, but it could not be seen. Shortly after, at around 0644, the Deer Island Princess II touched bottom on the north point of Jameson Island.
The Deer Island Princess II had a similar previous occurrence in 2018 where the vessel made bottom contact while transiting from Butler Point to Letete. Following an investigation into this occurrence, the TSB published Marine Investigation Report M18A0001. The report indicated that the hazard posed by normal operations in times of extreme low tide was not identified, and mitigation strategies were not put in place to reduce the associated risk.
Since the 2018 occurrence, the TSB received reports of 2 occurrences where Coastal Transport Limited vessels touched bottom or grounded in this same area at extremely low tides. The TSB notes that the passage plan currently in use by the ferries identifies 2 shoals that each have a chart datum of 2.2 m as areas that should be avoided when water depths do not allow for a 1 m clearance. Although the water depths in the channel also have a chart datum of 2.2 m and do not allow for a 1 m clearance during some low tide cycles, there are no mitigation strategies in place to address the associated risk.
The foregoing is provided for whatever follow-up action is deemed appropriate. An investigator may follow up with you at a later date. As the identified safety issue associated with this occurrence has been brought to your attention and consideration, is it anticipated that an investigation report will not be issued.
Original signed by
Marie-Hélène Roy
Acting Director, Marine Investigations Branch
Cc. Position, Transport Canada