Entering fog
You will probably have some warning before being enveloped in fog. You may see it looming ahead of you but, if you are not keeping a good all-round lookout, it could roll in from astern and catch you by surprise. When everything starts to look grey take the following actions as soon as possible. Some of them will need your careful judgement.
1 Lights
Turn on your navigation lights. The aim is to be seen at all costs, and dense fog probably justifies bending the rules and showing as many lights as you can – perhaps including an all-round white anchor light at the masthead. Better, I suggest, to risk a rebuke for showing incorrect lights than be involved in a potentially disastrous collision.
2 Sails
Make yourself visible. If you are motoring, keep the mainsail hoisted and consider having the headsail at least partially unfurled so long as it doesn’t obscure your view. To keep your options open for rapid manoeuvring, however, lower spinnakers and cruising chutes, avoid poling out headsails and unrig preventers.
3 SPEED
A yacht is unlikely to be able to exceed a ‘safe speed’, but sailing too slowly just prolongs the misery and makes any alterations of course less obvious on another vessel’s radar. In these conditions, motoring might make sense.
4 Engine
Have it running or ready for immediate use. The noise of the engine will reduce your ability to hear other ships, but you may think that instant manoeuvrability is more important in the circumstances. If you are sailing well and are confident that the engine will start on demand, I would leave it off (but see the point above).
5 lifejackets and HARNESSES
Put on lifejackets. Not only is this a sensible precaution, it also alerts the crew that conditions may become serious.
In calm weather (quite likely in fog), you don’t want to be tethered to the boat in the event of a collision, so probably best not to hook on. This has to be weighed against the risk of someone falling over the side, as recovering an MOB in fog or rough seas is going to be much more difficult.
6 liferaft
Have it ready to deploy. If it is normally stowed in a locker, get it out and secure its painter to a strongpoint.
If you don’t carry a liferaft, a possible alternative is to inflate the dinghy and tow it astern. It’s also worth having your EPIRB or PLB, and a flare ready to hand if the worst were indeed to happen.
7 RADAR
The rules require that proper use shall be made of radar, if fitted. This includes plotting and assessing contacts, so give the job to the most experienced operator.
As the skipper, this may be you. At the chart table, you are well placed to build up a picture of what is around you using radar, AIS, VHF and any reports from your team on deck in order to make the right decisions.
8 Sound SIGNALS
There is no way your fog horn is going to be heard inside the bridge of a large ship, but it will alert other yachts to your presence.
Anyhow, the rules say it ‘shall be used’. On our boat, we use a referees’ whistle for making sound signals. It is just as audible as a canister fog horn, and it doesn’t run out of gas.
9 lookout
A good lookout, by both sight and hearing (Rule 5), is essential. Brief your crew to report anything they hear or see. Warn them that direction can be ambiguous in fog, so ‘I think I can hear a big ship’s engines somewhere to port’ is likely to be more use to you than a guess at a precise bearing – which is quite liable to be wrong.