From: Tim Duffy via W3LIF <[email protected]>
Date: February 11, 2023 at 12:13:54 PM EST
To: <[email protected]>
Subject: [MCARC] More Bouvet
Reply-To: Tim Duffy <[email protected]>Here’s a longtime sailor's take on the situation. Have not seen any details on the Ham outlets so this is focused on the boat issue.
Marama is an amazing vessel designed for sailing in the Antarctic/Artic waters. At a 100+ feet you might thing she’s a big boat. In terms of the immensity and power of the ocean she is most decidedly NOT. Especially in the Southern Ocean - Antarctic regions. A mere pea in a very large cup to be thrown around at will. There are not many vessels better suited to the challenge than she. But still… While the loss of Brave Heart was deemed a loss by some, in reality this was no doubt a good thing for this venture.
While the issues of high winds etc. are pretty clear to most in regards of the shoreside team I doubt the issues surrounding Marama are as clear. Not to rain on anybody’s parade, but in addition to the team members literally putting their lives on the line so we can work a new one these are just a few things to consider regarding the transport vessel..
The Delete key is readily available.
As the link to the weather forecasts I sent before indicated there are several serious low pressure systems in the area. The island, most desolate etc., on the planet, has a reputation well deserved. This is a seriously dangerous part of the Southern Ocean. What are the risks vessel-wise?
WINDS
It’s all about strength and perhaps more importantly direction. If the wind is coming from the West to perhaps NW no big deal. Marama is anchored in the “lee” in sailor speak. In the wind shadow. The island protects her from the full force of the winds. Like stepping behind a building, car, tree, or other fixed object to reduce the impact. Life is good.
If the wind clocks around further North, as the forecasts seem to suggest then things get more risky. She will be exposed to the full force of the wind and even worse to the waves the wind generates. See next section.
WAVES
These are the killers. Wind sure, a big deal.. Waves deadly, nothing worse for a vessel at anchor.
Waves are created by the friction of wind flowing over the water. Mud puddle, pond, lake, ocean, it’s all the same. The water is dead flat, perfect mirror surface until the wind starts blowing. Starts out as a tiny breeze, there are ripples. Wind builds a bit the ripples get bigger. The sequence continues and pretty soon the waves are crashing about and things get serious. Nothing has changed other than the wind strength, the time it had to interact with the water, and the distance over which it flowed over the water. Laws of physics. Nothing more. Mother Nature is not angry nor out to get us. No emotion involved. Just two of the most powerful forces on the planet, wind and water doing their endless dance. Any vessel out there is riding along on a convoluted boundary between those two incredible forces. A magic, but vulnerable place to be. Doing it puts one in touch with the Universe in ways not otherwise available not even via prayer.
ANCHORING
In the case of Marama she is anchored in what a sailor would be generous in describing as a “roadstead”. A patch of water with no protection from any direction. A potentially dangerous anchorage in any circumstance. Why is that?
The Bottom
The bottom in areas like this are usually broken rock and boulders. Little if anything for a vessels anchor to catch on in a reliable way. In the S. Pac. the anchor may get to dig many feet into sand where it holds well. In areas in the Southern Ocean and other similar areas, it is a huge gamble. Your odds are way better with the Power Ball lottery. This is seriously dicey on every level even with a top notch experienced crew. Set the anchor on arrival and all is good. As soon as the wind changes direction all bets are off. The professional crew on that boat always has at least one or more crew members awake and on watch 24 hours a day. Always on the look-out for weather changes and the slightest indication that the boat is not on station where it is supposed to be. GPS anchor points set, shore-side visual sites monitored during daylight. Nothing is left to chance. If that wasn’t the case they wouldn’t have made it as far as they did.
Waves
Anchoring is always a gamble. You drop this chunk of heavy metal in the water, back the boat up to try and “set” the anchor in order to try to get it to dig into the bottom and hold the weight of the boat against wind and tide. In the Tropics it is not uncommon for crew to dive overboard and swim down to verify the anchor is “set”, not fouled on a coral head etc. I did it in places I was concerned about. In the freezing waters of the Antarctic not so much. Water depth is also a big thing. The deeper the water then the longer the anchor rode/line/chain needs to be to allow the anchor to work properly. It’s all very complicated.
While the uninitiated would likely focus on the wind strength as the biggest risk factor for a vessel at anchor, in reality the waves are the thing. If a vessel is anchored in the “lee”, protected by an island no big deal. However as the wind clocks around and the vessel is now subjected to the full force of the wind as well as the waves generated that’s when things get serious. The distance the wind blows over the water with no impediments to its flow is called “fetch” . More fetch is a bad thing because that means the waves just get bigger.
As the wind works on the waters surface and their height builds the stresses on the boat grow significantly. The boat usually swings into the wind. The waves usually but not always follow. As the waves build and get bigger the boat pivots up and down from front to back as the bow rises and falls along with the wave pattern. That’s called “pitch”. As the wind whistles by and often changes its direction even in small increments the boat “yaws”, meaning the bow turns rapidly side-to-side i.e., left/right. The combination of these movements puts enormous stresses on the anchor itself as well as the anchor “rode’, chain etc. that attaches the anchor to the boat as well as the anchor gear, anchor windlass, cleats, chocks etc. As the waves pass there will be tremendous shocks loads transferred to the anchor gear. On a vessel the size of Marama those stresses likely easily peak to load spikes in excess of 20,000+ pounds. This is serious stuff. Nothing but the best hardware and careful vessel management can survive these situations.
Wind Against Waves
I don’t have the necessary charts and other navigation/publications handy for that area so I can’t say for sure this is an issue in this case but here’s another worst case consideration
As previously noted wind blowing over water causes waves. But that’s just flat unmoving water. The laws of physics deliver an entirely different scenario if by chance the wind is moving in one direction and due to tidal flow or an ocean current off the island for example, the water is moving in the opposite direction. Wind against current, wind blowing across water into an opposing current can be a disastrous situation in even the best of circumstances. Everything changes. The waves generated are often twice as high. The waves have an entirely different shape… instead of the usual smooth roundish synodal shape they are more like a square wave. They are always much closer together. So if the wind is blowing and there is an opposing ocean current then that will make Marama’s anchorage totally untenable and very, very dangerous.
If the wind stays out of the North that’s bad enough, If the big low pressure system clearly visible in the link I sent earlier shifts more to the East then the boat risks being driven ashore to crash on the rocks if the anchor fails. Likely many lives could be lost.
Every competent mariner, and even less competent mariner’s such as myself, would always put out to sea to escape anchorages that are that risky. I’ve done it. The open ocean is far, far, far safer than being trapped on a lee shore with the wind howling, and the waves building and if and when the anchor fails all is lost.
Don’t be surprised if the weather changes and Marama hoists its anchor and gets underway to save itself and all on board. Only a fool would not.
As others have suggested the RIB (Radio In a Box) approach would make the best sense in a situation like this. But of course another question is why the ARRL, an organization I’ve been a proud member of continuously for over 50 years, continues to support “entities” that require people to literally risk their lives to put on the air. Really? For what? A scrap of paper or a few LOTW bytes?
If the current weather forecast holds don’t be surprised if Marama hoists its anchor and heads to the safety of the open sea.
73,
W7TMT
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