Monday, September 11, 2017

Transportation Safety Board Finds Large Wave Caused Leviathan II Capsizing

On June 16th the Transportation Safety Board released its investigative report on the capsizing of the passenger vessel Leviathan II. A summary of the report follows.


On 25 October 2015, at approximately three o’clock in the afternoon, the passenger vessel Leviathan II was on a whale-watching excursion with 27 people on board when it capsized off Plover Reefs in Clayoquot Sound, British Columbia. The subsequent rescue operation recovered 21 survivors, which included 18 passengers and 3 crew members. There were 6 fatalities. As a result of the capsizing, approximately 2000 litres of fuel leaked into the water.

The Operations

The operator and owner of the vessel, Jamie's Whaling Station Ltd., has been conducting tours out of Tofino and Ucluelet, British Columbia, since 1982 and operates a fleet that included 3 small passenger vessels and 6 rigid-hull inflatable boats (RHIBs). It offers whale-watching excursions seasonally from March to October, and approximately 25 000 passengers travel on these vessels each year.
A typical whale-watching trip takes 2.5 to 3 hours, and the vessels travel various routes between the south end of Long Beach and Rafael Point on the coast of Flores Island, a distance of approximately 28 nautical miles. These routes change depending upon weather conditions and the locations where whales and other marine wildlife, such as sea lions and otters, are most likely to be found at any given time. As part of the experience, in order to observe wildlife, it is not unusual for the vessels to pass close to land, and the vessels routinely travel near Plover Reefs.
Whale-watching excursions are weather-dependent, and trips are cancelled when conditions are likely to affect the comfort and safety of passengers. The company relies on the masters to determine when a trip must be cancelled because of poor conditions.
On 25 October 2015, 24 passengers arrived at the whaling station in Tofino for a whale-watching trip on board the Leviathan II. The master had checked the weather forecast on the Environment Canada website before the voyage, which was his first of the day. The forecast predicted southeast winds at 15 to 25 knots, becoming variable at 10 to 20 knots in the afternoon, and becoming northwest at 15 to 25 knots in the evening. The wave-height forecast predicted seas of 2 m, building to 3 to 4 m in the afternoon, and subsiding to 2 m near midnight. The master also checked the wave conditions recorded at the La Perouse Bank weather buoy. The significant wave height was between 2.6 m and 2.9 m, with a wave period of 9 to 10 seconds. The weather forecast was also available at the whaling station for the information of passengers.

While the Leviathan II was proceeding to Plover Reefs so that the passengers could observe sea lions, there was a swell of approximately 2 m from the southeast. On approaching Plover Reefs, the master visually assessed the sea conditions and checked for the presence of breaking waves, in particular at a spot south of the reef that the company's masters commonly used to determine prevailing conditions. There were no signs of breaking waves or aerated water or foam in the surrounding area, other than on the edge of the reef itself.

The Leviathan II first proceeded along the south side of Plover Reefs and then made a 180° turn and returned to the southeast side of the reef, where the sea lions were located, to provide passengers on both sides of the vessel with an opportunity to view them. Shortly before 1500, the master was maintaining the vessel's position on a northerly heading approximately 100 m off the reef in water that was approximately 7 m deep while the passengers were watching the sea lions on the port side. As the vessel was departing toward the north side of the reef, the master and one deckhand heard a noise and looked aft, at which time they saw a large breaking wave bearing down on the vessel's starboard quarter. The top of the wave was reported to be above the flying bridge. The master reached for the throttles in an attempt to turn the vessel to port so that the vessel would encounter the wave on the stern. However, at that moment, the wave struck the vessel's starboard quarter, causing the vessel to broach and rapidly capsize.

As the vessel capsized, one deckhand and most of the passengers fell into the water. The master and the other deckhand were initially trapped inside the flying bridge.

Twenty-one survivors were rescued and transferred to Tofino, where they were attended to by emergency health services. Some of the passengers suffered from hypothermia, ranging from mild to severe. Five bodies were recovered on the day of the occurrence and, one remaining passenger was found on 18 November 2015.

Vessel and Personnel Certification

The Leviathan II was certified, manned, and equipped in accordance with existing regulations.
The master and crew were adequately certified and experienced.

The stability booklet for the Leviathan II was approved by Transport Canada (“TC”) on 12 December 1996, and a copy was stored on board the vessel.
In order to assess the stability of the Leviathan II at the time of the occurrence and factors that may have affected it, the Transportation Safety Board (“TSB”) developed a detailed computer model of the vessel and performed various stability calculations. The conclusions of this TSB stability assessment are as follows:
1. The modifications that were made to the vessel since it entered service in 1996 resulted in a small change to the estimated lightship weight and centre of gravity and did not have a significant impact on the stability of the vessel.
2. With consumables, passengers, and crew distributed as at the time of the occurrence, the vessel's stability met and exceeded TC stability standards for normal operating conditions.
3. The results of the stability assessment with applied waves are consistent with the observed behaviour of the vessel at the time of the occurrence; that is, a rapid capsizing to port after having been struck on the starboard quarter by a large steep wave. The evaluation did not point to passenger load and distribution as being a likely factor affecting the outcome of the occurrence, nor were any other possible contributing factors identified, such as water ingress.
4. The stability standards established by TC do not explicitly evaluate a vessel's risk when operating in a wave environment. Although compliance with the standards implies a measure of safety against capsizing in a seaway, the standards do not address exposure to extreme circumstances such as large breaking waves or surf-like conditions. In this regard, TC stability standards are consistent with international standards in warning vessel masters that operational measures must be taken to mitigate the risk of capsizing according to the prevailing circumstances.
4. The results highlight the significance of encounter angle as a factor affecting the vessel's stability in waves. Specifically, the risk of capsizing is significantly reduced when the encounter angle is such that the vessel is meeting the wave head on.
5. The risk associated with the absence of specific passenger controls for the Leviathan II in normal operating conditions was evaluated as low.
Cause of Capsizing
While the Leviathan II was at Plover Reefs to allow the passengers to view sea lions, the vessel maintained a position on the weather side of the reef, exposed to the incoming swell. As the vessel was leaving the area, a large wave approached the vessel from the starboard quarter. Moments before it struck the vessel, the master heard a noise that caused him to look aft and notice the wave. However, by this point, the wave was breaking and it was too late to realign the vessel in order to minimize the impact of the wave. The TSB stability assessment supports the conclusion that the forces exerted on the vessel by this wave were sufficient to overcome the stability of the vessel and cause it to capsize; no other significant factors contributing to the capsizing were identified. In summary:
1.         While the Leviathan II was at Plover Reefs, the conditions were favourable for the formation of breaking waves.
2.         The vessel maintained position on the weather side of the reef, exposed to the incoming swell, to allow passengers to view wildlife. As the vessel was leaving the area, a large wave approached the vessel from the starboard quarter.
3.         Moments before the wave struck, the master became aware of it and attempted to realign the vessel to minimize its impact, but there was not enough time for his actions to be effective.
4.         The forces exerted on the vessel by this large breaking wave caused it to broach and rapidly capsize.
5.         The rapid capsizing resulted in the passengers and crew falling into the cold seawater without flotation aids or thermal protection, exposing them to the effects of cold water immersion.
6.         Approximately 45 minutes elapsed before search-and-rescue (“SAR”) resources became aware of the capsizing, as the crew did not have time to transmit a distress call before the capsizing, nor did the vessel have a means to automatically send a distress call.
7.         The crewmembers were able to discharge a parachute rocket, which alerted a nearby Ahousaht First Nation fishing vessel that was instrumental in saving the lives of a number of survivors.
The TSB made the following recommendations that:
1.         The Department of Transport ensure that commercial passenger vessel operators on the west coast of Vancouver Island identify areas and conditions conducive to the formation of hazardous waves and adopt practical mitigation strategies to reduce the likelihood that a passenger vessel will encounter such conditions.
2.         The Department of Transport take steps to ensure that small passenger enterprises have a safety management system.
3.         The Department of Transport require commercial passenger vessel operators to adopt explicit risk management processes, and develop comprehensive guidelines to be used by vessel operators and Transport Canada inspectors to assist them in the implementation and oversight of those processes.
4.         The Department of Transport encourage all charter vessel operators to equip their vessels with life-saving and emergency communication and/or signalling equipment suitable for the type of operation.
5.         The Department of Transport require small passenger vessels to provide pre-departure briefings and to be equipped with a life raft that is readily deployable, lifesaving equipment that is easily accessible, and the means to immediately alert others of an emergency situation.
6.         Transport Canada should consider whether requirements for the use of digital emergency beacons should be applied to additional classes of boats and airplanes.

7.         The Department of Transport expedite the proposed changes to the Navigation Safety Regulations and expand its current emergency position-indicating radio beacon (EPIRB) carriage requirements to require that all commercial passenger vessels operating beyond sheltered waters carry and EPIRB, or other appropriate equipment that floats free, automatically activates, alerts search and rescue resources, and provides continuous position updates and homing-in capabilities.


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