Just a few minutes of sailing in dense fog takes most sailors well out of their comfort zones: it\u2019s disorientating and, quite frankly, scary for many. Here are some tips on how to prepare for, and deal with, a \u2018pea soup\u2019Sailing in fog can be exhausting and disorientating. Photo: Carlo BorlenghiAt sea, fog can be summed up as condensed water vapour or just thick cloud on the surface. Sea fog, or advection fog, forms when relatively warm moist air moves over colder water and cools to its dew point temperature, causing the air to saturate.
\nUnlike land fog, or radiation fog, sea fog can occur at any time of day and still exist with quite strong winds. It only really clears with a change of air mass \u2013 usually with the passage of a cold front. Without the passage of a cold front, it can last for days.
\nWhile radiation fog usually occurs on cold, still winter days, sea fog or advection fog is more prevalent in early summer. June can be a particularly bad month in the English Channel, when the water is still relatively cold, with warm moist air coming up from the south-west.
\nThese Sat24.com website images reveal that what appears to be cloud in the satellite view\u2026
\nLooking out for the forecasts of fog is important, but one simple trick is to go online and use satellite imagery. Sat24.com is a great website to see the last three hours of visual imagery, where fog often shows as a dull, grey and featureless cloud. Next, do a quick comparison with the infra-red satellite imagery and the fog seems to miraculously disappear, whereas other clouds tops still show up.
\nThis is due to the fog being approximately the same temperature as the sea, hence giving a neat confirmation of the existence of fog on the visual picture. You can then return to the visual imagery and more accurately plot the extent of the fog and potentially take avoiding action.
\nCaught in fog
\nIf you unexpectedly end up sailing in fog, first consider whether you need to keep heading further into it? Would it make more sense to do a quick 180\u00b0 turn and head back out into clearer visibility?
\n\u2026is in fact fog that disappears in the infrared view as shown here in the Celtic Sea and North Atlantic
\nOnce we realise we\u2019re sailing in fog, we need to work through a checklist of actions. Note your compass heading. Do we need a more experienced helmsman? It\u2019s easy to quickly find you\u2019re 30\u00b0 or 40\u00b0 off course and not notice. Steering is more exacting and even exhausting.
\nCould it be less stressful to use the autopilot, to allow you to focus on lookout? Just be ready to immediately switch to manual if you need to at a moment\u2019s notice.
\nSlowing down is certainly good seamanship and the requirement to proceed at a safe speed appropriate to the conditions is detailed clearly in the International Regulations for the Prevention of Collision at Sea (IRPCS Rule 6 \u2013 Safe Speed).
\nArticle continues below\u2026<\/p>\n
\t\t\t\t\t\tWeather expert Chris Tibbs on how to predict and cope with fog at sea<\/p>\n
\t\t\t\t\t\t\tRadar and AIS help to make navigating in fog safer, but it is still an unnerving experience to sail in\u2026<\/p>\n
\t\t\t\t\t\tNavigation briefing: Mike Broughton explains why you still need radar<\/p>\n
\t\t\t\t\t\t\tIn a recent feature in Yachting World, my friend and highly respected yachting journalist Ed Gorman wrote a revealing article\u2026<\/p>\n
With an increased risk of collision, it\u2019s good practise to ensure everyone is wearing a lifejacket. Maintaining a proper lookout is essential. In \u2018pea soup\u2019 fog, stationing a person forwards near the bow can help enormously. If motoring, the bow is a good place to escape the noise to allow the lookout crew member to listen for fog signals, or other hazards. On several occasions when I\u2019ve been sailing in fog, the lookout at the bow has provided vital information to avoid a hazard or navigation mark.
\nIn areas of dense shipping, remember to look up as well as straight ahead, I\u2019m sure I am not the only person to have sighted a large vessel from the helm at the angle of the first spreader!
\nWhen \u2018in or near areas of restricted visibility\u2019 IRPCS states we shall make the prescribed sound signal, which for sailing vessels is one long blast, followed by two short blasts at intervals not more than two minutes. We need to have a working knowledge of sound signals of other vessels: many don\u2019t appreciate that the fog signal for yachts is the same as vessels involved with fishing, towing, and even vessels \u2018constrained by draught\u2019 and \u2018not under command\u2019.
\nMake yourself visible
\nTo help other ships see us, our best chance is to ensure we are clearly seen by the equipment on the bridge, which is radar and AIS (automated information system). Radar is a great help, but not all yachts have it, and it does take concerted focus and an understanding of how best to use it. Nearly all yachts have radar reflectors. Disappointingly tests have shown radar reflectors are not as effective at enhancing our radar signature as many people think. Active radar transponders show up much better.
\nAIS has been a real step change to aid collision avoidance when sailing in fog, though always remember that not all vessels use it and it is only an aid, albeit a very useful one. AIS can give the speed and course of a vessel as well as the closest point of approach (CPA) and time to the CPA: this is really useful data when navigating in fog. AIS also gives the vessel name, call sign, type and size.
\nNavigation lights are essential in foggy conditions. In a really thick fog the bow navigation lights can reflect back off the fog, leaving you with an eerie red or green glow.
\nDo you know how to make the prescribed sound signal in restricted visibility?
\nThe amount of radio traffic tends to rise when sailing in fog, though beware using VHF radio to communicate with the watch keeper of another vessel, which can be fraught with problems.
\nThere have been at least three occasions in the Dover Straits where watch keepers have opted to use radio to try to negotiate collision avoidance, which has ended unhappily in a collision!
\nThese have often come about through misidentification and language difficulties, when both watch keepers should have prioritised normal rules of the road and not allowed themselves to be distracted in an important close quarters situation.
\nOne tactic for dealing with fog on small vessels is to head away from busy shipping channels and sail to shallow water and anchor. Once tethered to the seabed remember to sound your fog signal (for vessels over 12m, ringing a bell for five seconds every minute). Many sailors may not be familiar with the additional signal of one short, one long, one short blast that can be made after the bell if you are concerned of a risk of collision while you are an anchor.
\nStopping and racing in fog
\nRacing in fog creates extra challenges. Fog by night can take you by surprise and it is easy to lose hard fought gains, if the helmsperson loses awareness. If you have the choice of tacking into fog or not when racing, I would take the clear option every time: humans concentrate better when they can see.
\nThe disorientation and confusion that sailing fog can create can easily generate high levels of stress. Mat Sweetman, captain of the J Class yacht Rainbow, suggests: \u201cIt is easy to get freaked out in fog, [but] look at is as if it was just a dark night and it gets a whole load less stressful.\u201d
\nOne clue as to the existence of fog at night is an absence of ambient lights and low altitude stars. If you are on the helm and getting close to fog, it is a good idea to start a scan of your yacht instruments. Like a pilot flying into cloud, it is imperative to \u2018believe in your instruments\u2019.
\nA regular scan is most effective but is both tiring and exacting over a long period of time. On top of normal sailing skills such as utilising the feel of your helm, tell tales (if you can still see them) and heel angle, we now need to bring in regular glances at true wind angle, boat speed, and heading. Working out a pattern for your scan is a good discipline for sailing in fog.
\nSea fog is renowned over the Grand Banks. On the Transatlantic Race in 2005, fog prevailed for over six days with sustained wind speeds of 25-30 knots. Visibility was mostly less than 150 metres. Sailing in fog for nearly a week is tough going!
\nUsing radar for collision avoidance
\nPeriodically cycle through the ranges and don\u2019t leave it just on long range. Zoom in to only three miles in busy shipping and even closer when tracking a vessel of interest.
\nLeave the sensitivity and clutter settings on auto. Modern radars handle them well.
\nIf you want to look through a rain cloud, alter \u2018rain clutter\u2019 control very briefly, then revert it to automatic every time.
\nUse a split screen with radar on dual range, or radar and chartplotter lined up alongside, or radar \u2018overlaid\u2019 on the chartplotter.
\nExperiment with this before you hit fog.
\nConsider setting up an alarm zone to help you detect contacts.
\nIf your radar display is below decks, have a tested system for communicating to the helm. Some yachts use a private VHF channel.
\nStay clear of busy ferry routes
\nFirst published in the November 2020 issue of Yachting World.
\nThe post Sailing in fog: Pro navigator Mike Broughton shares his top tips appeared first on Yachting World.<\/p>\n","protected":false},"excerpt":{"rendered":"
Just a few minutes of sailing in dense fog takes most sailors well out of their comfort zones: it\u2019s disorientating and, quite frankly, scary for many. Here are some tips on how to prepare for, and deal with, a \u2018pea … <\/p>\n