Seamanship: The OODA Loop

I was nearing the end of my watch at 11 p.m., 150 nautical miles off the northwest Australian coast, when I peered around the dodger on our 35-foot sloop to catch a better look at our sails. It was, as a friend described it, “champagne conditions”—15 knots aft of the beam, a low swell from behind with a skinny moon and streams of phosphorescence piercing the offshore dark. The genoa was filling beautifully, as was the main, although it looked a little full and the boom a little too high.

I was just weighing whether it was worth tensioning the vang as my eyes traced the boom to the gooseneck and stopped in horror where the vang attached; the boom was angled about 35 degrees at this point, bent upwards and, as my eyes adjusted, shaking somewhat.

My stomach dropped as the magnitude of the problem sunk in. We were three days into an 11-day passage, had been without reception or radio contact for almost the entire time, and had no satphone to check the forecast or get external advice. I calmly but quickly woke the crew, my partner, Sara, and friend, Klaus. It had not been a catastrophic failure, and we were still sailing along fairly quickly. We had a few minutes to think and needed to make the most of those.

As luck would have it, I’d recently been listening to a podcast about something called the OODA Loop. Although it may sound like the reef knot’s wacky Swedish cousin (mention the OODA Loop in a yacht club and I’m sure you’d find someone claiming the ability to tie one blindfolded), this refers to a decision-making process created by military strategist and U.S. Air Force Col. John Boyd. It stands for Observe, Orient, Decide, Act, and even though my understanding of it is still pretty basic, I’ve found it a useful tool that should be in every sailor’s mental toolbox.

The beauty of this process is twofold: First, by forcing us through steps, it dissuades rushed decisions and slows our panic, guiding us towards what our “calm minds” might normally come up with. Second, in making us interrogate and make explicit what we implicitly think we know, it can help us realize the uncertainties we face and plan according to these unknowns.

Depending on who you learn from, there are many different emphases and interpretations, but the underlying process remains the same. Now, within a few hours of hearing about this for the first time, I decided to use it to lead us safely out of the situation we found ourselves in.

Step 1: Observe

This is essentially information gathering, but differentiating between pertinent information and so-called noise requires a high degree of situational awareness. As sailors, we are constantly trying to form as complete a picture as possible, and we regularly juggle different inputs to make sense of our ever-changing surroundings. If we see a disrupted patch of water, is that an overfall because of a stronger tide than anticipated? Is there a bathymetry change in the area A school of fish? We must examine the area of interest, our surroundings and auditory inputs, and draw on our (often imperfect) geographic, meteorological, and tidal data to make sense of the phenomenon while recognizing that it may also be the result of something we do not know or cannot observe.

In our case, my initial call to wake the crew ensured that someone could replace me at the helm and let me proceed, with head torch and harness, to more closely inspect the boom and reevaluate the conditions. A crack, about half the height of the boom and about 1.5 inches wide at the bottom, split the boom almost completely. It appeared to have started from the bolts joining the vang fitting (stainless steel) to the boom (aluminum) and I could see some evidence of corrosion between them.

The boom seemed stable enough, but every time we got a gust the crack would flex alarmingly. A quick check over the rest of the rig satisfied me that this was a relatively isolated problem, but given that it was essentially just the track and an inch of aluminum connecting the two halves meant that we’d have to address it fast. The conditions had been fairly stable for the previous few hours, and we were not expecting any major changes, although the wind was strengthening slightly. A quick look at the barometer (our sole forecasting tool) would’ve been useful to confirm this but was something I omitted in my haste.

Step 2: Orient

This step, possibly the most important, involves building a mental model that fits our circumstances and bringing in our greater environmental information, or lack thereof. It is particularly crucial when we repeat our loop and, in the face of uncertainty, reconfigure our model. Boyd refers to this as a process of “destructive deduction” and “creative induction,” breaking down our existing models into their constituent parts and reassembling them to form something that better fits our situation.

Our orientation, and the models we can draw from, are a direct result of our broader knowledge, so Boyd advocates for developing your understanding in many different spheres. For sailors, a basic understanding of math, physics, fluid dynamics, mechanics, meteorology, oceanography, and even psychology would allow for a variety of different mental models at hand. Of course, some of these are intuitive—and I’m not suggesting a return to K-12 for Wednesday night racing—but the point is, the more rounded our knowledge, the more mental tools we have to better understand any situation.

A pertinent point is that we must consider, objectively, ourselves. Knowing our history and character lets us place ourselves along a spectrum of different traits and prepare our plans accordingly. If we lack confidence or are particularly risk-averse, we may gravitate toward ideas that seem easier or less dangerous although they may not be the best solution. Conversely, if we know we are gung-ho or highly skilled, we may gravitate toward dangerous or showy decisions that—you guessed it—may be unwise.

We also must consider uncertainty; we are always working with imperfect information in an ever-changing environment, so although we might not be able to construct a perfect mental model every time, we can at least develop our powers of orientation and test our mental models as situations unfold.

In our cracked boom scenario, I had two distinct phases of orientation, one after the initial discovery, and a second once the situation was somewhat stabilized. On realizing the boom had cracked, I had to intuitively call on a bit of material and physics knowledge. It didn’t make sense to me that it hadn’t already snapped, so I knew I had to reconfigure.

My intuitive mental model suggested that the boom gave all the lateral shape to the sail’s foot and that the force from the sail was applied along the boom. But I realized that the sheet, leading aft, was providing enough down (and lateral) force to maintain the sail shape regardless of the damaged boom.

The U-shape of the track meant that the top of the boom would be slightly stronger than the bottom, which probably prevented the catastrophic failure that would’ve knocked our socks off, and the foot of the sail gave its own vertical support to the boom.

My initial idea had been to steer up slightly and sheet out to relieve some tension but, on second thought, I realized the sail’s pressure was probably contributing to maintaining its weird equilibrium.

I also knew that I tend to rush through difficult situations on intuition and without enough regard for safety, so I slowed down and put safety first. Knowing that Klaus was mechanically savvier than myself, we had a brief planning meeting at the mast.

We both realized that simply dropping the sail would probably lead to more harm than good, with all the vertical force from the topping lift applied far from the crack and almost certainly snapping it in two, so we had a rummage through the toolboxes—physical, environmental, and mental—to concoct a solution. We examined all the lines—halyards, lazyjacks, reefing, and sheets—plus the materials we had and ran through some possible ideas to bring the sail down and stabilize the boom without further breaking anything.

The second orientation was post-stabilization.

We had to weigh several factors, including our distance to shore (already large and only increasing), the potential availability of parts for a repair at different ports/countries, our visa situation in either Australia or Indonesia (we would have to declare ourselves as “distressed mariners” to be allowed back into Australia as non-residents, and needed to be in Indonesia by an ever-looming date to start our next visa), predicted weather conditions for the next week, and our psychological state—an important factor for a small crew. As skipper, I felt obliged to put our safety first and advocated for a return to the closest port, although my heart wanted to continue. But the response from Sara and Klaus was surprising: They wanted to push on if deemed safe and continue slowly on our way under genoa alone.

Step 3: Decide

Fairly self-explanatory: Here we simply weigh up the perceived pros and cons of our plans and pick which best fits our mental model and situation. For a sailing-specific situation, I think it’s always best to bring risk into our decision-making process and try to mitigate this as much as possible, particularly when it requires a bit more effort, as we’ll potentially be more inclined to take the easier, riskier solution.

We chose to proceed with caution and test our ideas as we went. We decided to sail as gently as possible to allow for easier deck work, splint the boom on one side with an oar and rope, and slowly drop the main after bringing the boom in and supporting it as much as possible.

Step 4: Act

Now, with a plan and model to guide us, we proceed with our chosen solution, all the while “looping” back and continuing to observe, reorient, and revisit our ideas as things unfold.

We had already furled the genny slightly to slow down a bit and had steered up to quell the rolling we’d felt running downwind. Now we sheeted in the main enough to easily work with the boom as we gently turned downwind again to bring some pressure off the now poorly trimmed main. Klaus and I tried to work quickly but calmly, Klaus holding the oar parallel to the aft section first as I tied and wrapped it with a thick line, and then pushing up on the forward section to close the gap somewhat as I wrapped this section, pulling the line as tightly as I could and succeeding in slightly closing the gap and splinting the break.

I slightly increased the tension on the lazyjacks, fastened beneath the boom at three points spread over the break, to give the boom a bit of support. We then attached a halyard just aft of the splinted crack to give the rear section more support as we dropped the sail. I took up tension on the topping lift to avoid any jarring movements, tied it off, and slowly let the main halyard out an inch to see how it reacted, watching the crack intently. This was not enough to change it, the sail simply taking a fuller shape, so I had to drop it about a foot before we could tell the weight had transferred to the topping lift, press-ganged halyard, and lazyjacks.

It seemed stable, so I dropped the sail the rest of the way and was glad to see the splint strain, but hold, as the weight transferred across the crack. With the sail down, we quickly sheeted it in fairly hard against the topping lift to prevent it swinging, and moved the traveler across so we could work on the high side to quickly wrap another oar handle on the other side of the crack. I was amazed at how much strength this seemed to give it, and we managed to take most of the angle out of the break. Never doubt the power of a decent line and a bit of aluminum!

Finally, I tightly wrapped the sail and cover to the boom (we have no stack pack) and tried to essentially create a low-profile, firm sausage of line, sail, and splinted boom. The worst danger now passed, I was confident that this would stand up to the blow predicted for the following day, so we set the full genny and resumed our previous course—only 700 nautical miles to Kupang!

Over the following days we revisited that evening in a series of discussions and thought about what we might do, or might have done, given different circumstances. We considered dropping the boom to the deck, removing it and replacing it with the spinnaker pole (just the right length, as it turned out), or even rigging a storm jib as a trysail taken straight back to the mainsheet and bypassing the boom completely—all interesting and potentially fun ideas that I now wish we’d explored more.

As it was, I was unwilling to lose or damage anything further (humans included) and decided that until absolutely necessary, we would coast along with the boom firmly splinted in place. Each morning check revealed our hasty fix to be a solid one, barely flexing even in rougher conditions. Together we started to put together options for the new boom, drawing up plans that we could try to implement with little or no marine-specific materials.

The rest of our sail was (relatively and thankfully) non-eventful, and we made fairly decent time under genoa alone. The boat balanced fantastically most days, as we had the wind just aft of the beam. We did not encounter any heavy weather until we had almost made Kupang, when the genny scooped up a wave as we heeled over and bent and ripped the track from the gunwale.

Again, an OODA Loop helped slow down and solidify my thoughts (I was shouted up from my bunk at 4 a.m. to have a look). We managed to get the genny furled, track stabilized, a block onto a steel tang nearby, and the sheet off the track and through the block, and continued on our way—a little more exasperated than before. In Kupang, we made friends with an old carpenter-boatbuilder who lived in a beach shack, and with his help and tools, and Klaus’ feeling for wood, we constructed a new boom from teak, and heated and bent the track back into shape.

The OODA Loop now forms a key point of my crisis management toolkit and has proved its worth in multiple scenarios. It can be observed, unnamed, in most accounts of successful crisis management and has been employed (often unwittingly) by many great sailors; reading an account of the first Golden Globe, I was struck by the methodical, intelligent manner in which almost all competitors had to assess their respective situations and choose a path forward—they were certainly OODA Looping before it was cool!

Tim Coles is a 25-year-old cruiser with a degree in marine science, sailing in the Indian Ocean aboard his 35-foot steely, Restless, with his partner, Sara, and Able Cat Tiga. Follow him @restless_sails.

October 2023