Yachting Monthly - April 2016

PRACTICAL SEAMANSHIPPRACTICAL SEAMANSHIP

James Stevens spent 10 of his 23 years at the RYA as Training Manager and Yachtmaster Chief Examiner

Pilotage

in fog

The odd hole in the fog can let

you make absolutely certain that

you are where you think you are

Pilotage in fog involves
making a plan and
staying on deck to avoid
traffi c and pick up any
clues on offer while
navigating buoy to buoy

32 http://www.yachtingmonthly.com APRIL 2016

V

isibility at Poole Town

Quay was a few boat

lengths. It was one of

those mornings when

the sensible option

would have been to put the kettle

on and read the paper or, more

constructively, service a winch,

sort out that fl ickering bunk light

or wander around a chandler’s

With an appointment to keep, James

Stevens goes against his better judgment

and leaves Poole Harbour in thick fog

buying something

useful but not essential.

Unfortunately, I

needed to set off for

an appointment in

Portland Harbour the

following morning.

The fog in Poole was

undoubtedly radiation

fog. It had been a

still night with high

pressure and the forecast had

indicated fog patches forming

overnight. Another clue is that

radiation fog is quite a thin layer,

so although visibility horizontally

was about 50 metres, vertically it

was sky-high. I would expect the

sun to burn it off by lunchtime,

but I needed to get around the

tidal gates of Anvil Point and

St Alban’s Head before the tide

turned foul at midday.

Chartplotters have made fog

navigation far simpler than the

days of creeping along contours

and complex time and distance

calculations. As a Yachtmaster

Examiner all that is in the back

of my mind but, although having

a screen to watch does simplify

the problem, there is still work to

be done in the form of a pilotage

plan before slipping the lines.

Courses between buoys, tidal

heights and streams all have to be

worked out beforehand.

Staying out of trouble

The chartplotter is great for telling

you where you are but it does not

of course tell you where everyone

else is. If you have AIS you can be

reassured that you will

miss something large,

all vessels over 300

GRT have to transmit

their position, but one

of 299 GRT could sneak

up out of the fog and

fl atten you. There is

always going to be a

risk whatever the screen

might tell you.

You can reduce that

risk by keeping out of

the main channel, in

shallower water where

ships can’t get you, and,

as Rule 5 of the Colregs

says, ‘Keeping a proper

lookout by sight and hearing as

well as by all available means.’ We

were aboard Tamora, my Hallberg-

Rassy 34, which has radar but

the display is at the chart table.

Although I had a photographer on

board he was not unreasonably

earning his money taking pictures

so I was left virtually singlehanded.

It seemed to me sensible to

spend the maximum time on

deck peering into the murk and

listening to foghorns and minimum

time in front of the radar screen.

The chartplotter is below too,

so I decided to navigate with an

My plan involved a sketch with range and bearing for

all of the buoys we would pass on the way out of Poole