Whale Watching Boat Capsizes in British Columbia

[jerrycando]

A rogue wave capsizd this large Whale-watching tour boat off the West Coast of Vancouver Island. Five British tourists died in this freak marine mishap.

http://news.nationalpost.com/news/canad ... ver-island

11209527_900730490005907_2559933799712372303_n.jpg (25.72 KiB) Viewed 9891 times

[jimh]

The capsized boat was the LEVIATHAN II, a 65-foot vessel. The tour operator's website gives some details:

https://www.jamies.com/site/whale-watch ... uiser.html

[JRP]

A rogue wave capsizd this large Whale-watching tour boat off the West Coast of Vancouver Island. Five British tourists died in this freak marine mishap.

http://news.nationalpost.com/news/canad ... ver-island

11209527_900730490005907_2559933799712372303_n.jpg

I could not find a reference to a rogue wave being the possible cause of this capsizing, in either of the links provided. Maybe I missed it.

[jerrycando]

The wave mention was made in oral accounts from passenger in the news telecast. Most [survivors] have remained rather tight-lipped due to obvious court and insurance concerns to come.

[jimh]

The term "rogue wave" seems to be imprecise and quite poplar among non-mariners and journalists. In any well-developed sea state, there is a statistical probability that a wave of about TWICE the height of the "significant wave height" will occur once every 1,000-waves. Note that "significant wave height" is the average height of the waves in the upper one-third of all wave heights, which means this is already a description that is more than just the average wave height; it's the average of the waves of the upper one-third of all waves. So twice the significant wave height is really a wave that is much larger than most waves. But such waves are not to be unexpected. They are normal events.

Let us say the period between waves was 6-seconds. In one hour there would be 600-waves encountered. That suggests that in a two-hour boat ride the boat would interact with 1,200-waves. Statistically it is very likely one of those waves will be twice the significant wave height. This is not really "a rogue wave" but just a normal event in any well-developed sea.

The LEVIATHAN II was rated to carry as many as 46-passengers. At the time of the capsize it had 27 passengers. If we figure the average weight of a passenger is 185-lbs, then 27 passengers of 185-lbs is about 5,000-lbs of moveable weight on the upper deck of the vessel.

[Spuds]

And with that many people on the upper deck, I would think that vessel may be quite top heavy.

[Dutchman]

Maybe they meant to say rogue whale as I assume like JimH you must get a hell of a large wave to cause this boat to capsize.
The boat wasn't that large and 25 on that top deck even if close to the the railing (not all 25 fit at the railing looking at the picture) therefore that weight is still relatively close to center-line due to side-decks below, so this might cause the boat to list slightly. Even if all ran from Port to Starboard to see a whale it must have been at that exact moment a breaching wave would lift the boat. Very unlikely with a Captain familiar with those waters and like any boater would take the waves quarterly.
They took on water very quick down below causing unforeseen instability resulting in the accident. not a "rogue" wave.
JMO (just my opinion)

[JRP]

...
They took on water very quick down below causing unforeseen instability resulting in the accident.... (just my opinion)

That was my thinking as well. But then we apparently have an oral report from a passenger attributing the accident to a large wave.

I don't necessarily place much stock in the report from passengers who may or may not have any experience on the water or with boats, but they were there and I was not. Most likely it was a combination of factors, as is often the case. And conditions can change rapidly as they did back in the 2004 Baltimore Water Taxi tragedy: http://articles.latimes.com/2004/mar/07/nation/na-capsize7

I'm sure the RCMP or Canadian Coast Guard will conduct a thorough investigation and eventually we will have some answers.

[jimh]

I don't know and have not speculated about the size of a wave that would be necessary to cause the LEVIATHAN II to capsize.

[cnickm]

I think you are all on the right track. I ran passenger vessels for almost nine years. Ours were mostly bigger than this one, but we did have one that was similar in size and shape.

The rating of 46 passengers is a vessel rating and not a upper deck rating. Our 72-foot boat was rated at 90 passengers, but only 24 on the second deck.

I would suspect that, as mentioned, most passengers were on the top deck and all looking at something off one side. There are a whole lot of other factors that go into the stability of the vessel. In 2011 we had to re-certify all passenger vessels capacity due to America gaining weight. It went from 160-lbs per person to 185-lbs as mentioned above.

You could go three different ways of taking the hit:

--you could go off of your current rating and take a passenger reduction based on a calculation by a naval architect

--you could weigh each passenger as they board and not exceed a certain weight--nobody did this one, or

--you could do a simplified stability test. This was a big gamble as you didn't know if you were going to come out with more or less passengers than the calculation test.

I would be curious to see which way this vessel went on the weight increase.