Conception Boat Fire Accident Analysis

Not an expert in this topic but basically I understand there are different methods and models of accident analysis.

The Swiss Cheese and the accident chain are two different models. Another a systems approach like Nancy Levenson’s STAMP.

Previous thread here:

This thread stems from this one:

The other thing is looking for a "root cause’ vs looking it as a system.

With regards to the COI this is from Nancy Leveson:

“As many human factors experts have found, instructions and written procedures are almost never followed exactly as operators try to be come more efficient and productive and to deal with time pressures”

It goes on to say there a difference between a deviation from formal rules and deviation from established practice.

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So looking at it as a cheese stack, we have:

  • Slice representing COI compliance, where normalization of deviance forms the hole. Can be controlled by regulatory pressure, which will likely follow now that the risk is properly understood.
  • Slice representing onboard awareness of accident potential, with the total lack of effective fire alarms forming a giant hole. Can be controlled by subchapter T refinement and enforcement.
  • Slice representing lithium battery safety, where the hole is a bad time and place of fire initiation. Can be controlled by limiting where and when batteries are charged on board.
  • Slice representing vessel specific fire survivability, where the Conception is a hole with her flammable construction and poor emergency egress. Can only be partially controlled given the poor survivability of the type of yachts whose design form the basis of typical dive boats.

I’m not as shocked as y’all that they thought it was OK for everyone to go to sleep, that is how practically all small yachts are operated, both privately and professionally. What really gets me about this one is the design of the guest quarters. I would definitely not have been comfortable sleeping there myself, and would have been extremely uncomfortable in charge of the situation. Indeed, this is something that should have spurred the crew and owners to have a close look at the rest of the cheese stack to see if the situation could be safely handled somehow.


Your post matches closely the NTSB recommendations;

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The T.J. HOOPER case (53 F.2d, 107 S.D.N.Y. (1931)) tugboat held liable for failure to have a radio to receive weather reports even though it was not USCG required, established as US General Maritime Law (judge made federal common law) that vessel owners must be forward looking and adopt new safety innovations, even if they are not yet USCG required.

Therefore, any vessel owner that fails to install a fire detection and alarm system in the 2000’s whether it is USCG required or not, should expect to be held liable under Maritime law for any injury or death that occurs in the absence of a fire detection and alarm system.


How many times have you had an owner of manager say: “that’s not USCG required”?

The problem is that the USCG is an inefficient, and too often incompetent, government bureaucracy that is often a few decades behind the times. The USCG rule making process is far too slow to begin with, but owners, and their lobby groups, like AWO, have too much input, and can easily delay new regulations for a decade, and water them down to the point where the accomplish very little.

Just look at Subchapter M! It was many years in the making, and the result is just a bunch of pencil whipped feckless paperwork, and soft glance pseudo-inspections by teenage lieutenants from Wyoming.

The owners and managers misunderstand. Just because the USCG does not specifically require something in the CFRs, a checklist, or the COI, that does NOT mean that it is not required. At the end of the day after an incident, the court will decide what was required.

The USCG may not require it, but if it’s an item that impacts safety that most companies in the trade routinely provide, then, its almost certainly going to be required by the courts. If it’s something that other vessels, in other trades, but with similar economic constraints provide, then it’s quite likely that a court will find that its required for you too. Even if it’s an item which few vessels are using, some judge may still hold that it’s affordable and it’s benefits are obvious, therefore, “it IS required.”

Who wants to be the owner or manager that sent an email denying a request for a common $1,000 safety item, saying: “No, it’s not USCG required”? Have you thought about how you are going to explain that at your deposition?


Thé problem is the USCG is an example of regulatory capture just as many federal agencies are.

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Unlike the error chain or swiss cheese model Leveson’s STAMP systems model is a hierarchy. At the bottom in this case would be boat and crew, next layer up is the company above that the regulators.

The higher parts of the hierarchy imposes safety constraints on the lower parts. The company and regulators are intended to constrain what the captain can do. For example the captain technically does not have the authority to cancel the deck watch but the system failed to constrain him (and evidently a lot of other captains as well).

Here’s another quote from Levenson.

Bottom-up decentralized decision making can lead, and has led to, major accidents… Each local decision may be “ correct ” in the limited context in which it was made but lead to an accident when the independent decisions and organizational behaviors interact in dysfunctional ways.

The decision not to have a roving watch may have seemed correct at the local level (on the boat) but in hindsight of course it was not.

Unless the weather is really bad we are all asleep at anchor on my boat*. I do have an escape hatch right over my head, a smoke alarm, and a CO alarm.
If it looks like we need to stand an anchor watch my first thought would probably be to go find a better place to anchor if I have to be up anyway.

  • no paying passengers, I mean my wife and I going someplace. If you went family cruising as a kid to working diveboats, you might not ever have seen anyone post an anchor watch in your life.

Or maybe an anchor watch in marginal wx conditions but rarely a roving security watch.


Here’s another good quote - they are in the book but I’m getting them from this site.

A system is not treated as a static design, but as a dynamic process that is continually adapting to achieve its ends and to react to changes in itself and its environment. The original design must not only enforce appropriate constraints on behavior to ensure safe operation, but it must continue to operate safely as changes and adaptations occur over time.

Changes that occur over time… in this case that could be the increased use of rechargeable batteries by passengers.

Here my take on the Boat fire accident analysis.
Read the NTSB report, it’s probably the best analysis you are going to see.
Given the limitations which come from a completely burnt out boat, having little to go on other than witness or survivor testimony and comparison with other vessel procedure.

They did pretty good.
The report contains a pretty good theory about what probably happened.
The report has pretty good theory why it probably happened.

The important part of the analysis is how to best prevent it from probably happening again.

If the NTSB recommendations are actually accepted and implemented it probably want happen again.

The public prosecutor is not happy leaving it there so criminal charges have been filed and a trail will probably take place.
At the end of which some one will be Guilty or Not Guilty.
Which in my opinion is not a very effective method of preventing accidents. But it is the way things work.

The hard part of our personal analysis of this incident. Is the finding a big contributing factor, existing regulations were not followed.
The rounds and apparently drills.

To some of us the answer to this question is common practice in the local dive boat community and industry.
To other the answer is somebody didn’t follow the regulations and broke the law.

Which leaves us with an important question outstanding.

Why did the Master and crew routinely not follow the regulations?
It was the common practice in this particular small company.
Possibly or even probably with other similar companies.

Leaving us still asking why did this company and others think this was ok.

Part of the answer is poor oversight by regulators. Partly because the regulator though they were a good company, And the regulator didn’t have a clue how to monitor or appear to have even contemplated monitoring the rounds.

A few years A Master I worked with,
Decided to take a part time business Management degree course.
Most of the concepts he tried learned about sound like BS to me.

One interesting concept

I think was call “Emergent Behaviour” Reading up on this will make your head hurt, all kinds of academic studies and papers. Applying this to all kinds of industries.

The very short version. As I understand it.

Any group of people (average humans) working together as a group, particularly if they are working in isolation.
Will gradually, unconsciously start to change the process or procedures of what they are engaged in and create their own rules.
Over time unless corrected, a group naturally creat their own rules and their own procedures which slowly deviate further from what was originally intended.

Additionally, most of these crews and masters probably started out on pleasure boats, moving up to these very small passenger vessels, learning from the guy ahead. Who came up the same way.
It is entirely possible even probable the regulations had never been followed correctly.

Is it possible, someone could look at a certificate only read it occasionally if ever and completely fail to understand what a roving patrol actually meant? For 30 years.

Apparently, Yes. Quite a few people.

The frustrating part. We don’t know why, He didn’t follow the regulations. Because the NTSB was never able to ask him.

The US DA requested the NTSB not to question the Master. In the interest of prosecution.

So it is entirely possible the Master will never be asked.

My limited understanding of American criminal law.
The accused Master has the right to remain silent.


This is from Robert Frump:

Ocean transportation is the one system that seems immune to safety improvement. Actually, it’s an “error inducing” system — where pressures for performance are high and the system is run by a disingenuous but convenient assumption: if any thing goes wrong, it’s the captain’s fault.


That’s a great quote.

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At some point a choice needs to be made about what we prefer: Do we want to find out what happened; or do we just want to prosecute the nearest scapegoat, particularly the Captain.

It is a great quote, and I believe that the observation that the marine transportation is an “error inducing” system is from James Reason, he developed the Swiss Cheese model and coined the term “normal accident”


I believe the term “normal accident” came from Charles Perrow.



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Yes, and I think the “error inducing” system was Perrow’s observation as well.

In his chapter on marine accidents, Charles Perrow calls marine transportation an " error-inducing " system.

Semper Paratus.

They have saved my life, boat and crew.