Lesson 8 of 13 · Module 3 — Close to land

Pilotage into a harbour or bay

Reading the pilot book page, planning the approach, leading lines and clearing bearings, picking the gap, the last mile into a marina, and arriving with daylight.

Day Skipper20 minVideo · Notes · Interactive · Exercises

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0:00 / 3:59Chapter 1 of 9: Pilotage into a harbour or bay

Transcript

Most charter trouble happens in the last mile, in the afternoon, with everyone tired. Pilotage is navigating by eye in that last mile, close to the rocks and the other boats. There is no time then to study the chart. So the thinking is done beforehand, and on deck you look, compare and tick things off.
Start with the pilot book page for the harbour or bay. It tells you which way to approach, what dangers lie off the entrance, and what you will see on the way in. It gives the lights, the depths and where visitors berth or anchor. It says which way the bay is open, and so which wind sends a swell inside. Read it the evening before, and again an hour out.
Now plan the way in on the chart, from a point you can recognise offshore. Here it starts at the Kerran Approach buoy, a safe water mark with deep water all round it. Break the approach into legs, from one mark you can recognise to the next. For each leg, note the heading, the distance and what you expect to see. Leg one is 003°M, one point six miles, about nineteen minutes at five knots.
Many harbours mark the safe way in with a leading line: two marks or lights, one behind and above the other. Port Kerran's leading lights are in line on 000°T, straight up the middle of the channel. If the rear light opens to the left of the front one, you are left of the line, so steer to starboard. If it opens to the right, steer to port. In short, steer towards the rear light until the two line up again.
Sometimes a danger lies near your way in, with no leading line to keep you clear. Arriving from the south-west, the wreck and Mew Rock lie to the west of the approach. So draw a line from the church spire that passes well clear of both, and measure it: 027°T, which is 030°M. Keep the spire bearing not more than that, and you stay on the safe side. Check it every few minutes with the hand-bearing compass until you are past.
From a few miles out, a harbour entrance can be very hard to see against the land. Look for the lighthouse, the end of the breakwater, or boats going in and out. Check the bearing of the entrance on the plotter, and look along it with the hand-bearing compass. Where the way in is through coral, as in the Caribbean, go with the sun high and behind you, so you can read the colour of the water. Then line up on the approach well outside, rather than cutting the corner.
Slow down for the last mile. Take the sails down outside the entrance, where there is room. Get the fenders out and the lines ready, and brief the crew on which side and what happens when. Watch the depth, and decide in advance what reading means stop. And know your way out, back along the line you came in on.
Call the marina before you arrive, by phone or on the VHF channel in the pilot book. Give the boat's name, her length, and how many nights you want. They will tell you where to go, and often a marinero comes out in a dinghy to guide you in. In most Mediterranean marinas you then go in stern-to, using the lazy line they hand you. Stern-to mooring is a skill of its own, so ask the marinero for help and take it slowly.
Plan every day to arrive with plenty of daylight left. Charter contracts often ban sailing at night, and unlit fishing floats and moorings are hard to see after dark. In the Seychelles it is dark by about half past six, all year round. So aim to be in by mid-afternoon, and if you are running late, choose the easier harbour.

In this lesson you will learn

Read a pilot book page and turn it into a short plan of the way in, leg by leg
Follow a leading line, and use a clearing bearing to stay clear of a danger
Pick out a harbour entrance, run the last mile with the crew briefed, and know your way out
Call the marina before you arrive, and plan every day to arrive in good daylight

Pilotage: the last mile, by eye

Most charter trouble happens in the last mile: in the afternoon, with the wind up, the crew tired and twenty other boats heading for the same quay. Close to land the marks come up every few minutes and the decisions come faster than you could ever work them out on the chart. Navigating by eye in confined water like this is pilotage.

The secret is that the thinking is done before you arrive, at the chart table or over breakfast. You prepare a short plan of the way in, and on deck you do not plot anything at all: you look up, compare what you see with the plan, and tick things off.

Plan at the table. On deck: look, compare, tick off.

Reading the pilot book page

The pilot book (or cruising guide) has a page for each harbour and bay, usually with a sketch plan. It is the single most useful thing to read before you arrive. Look for:

The approach: which way to come in, and the line to follow.
The dangers: rocks, shoals, reefs, wrecks, fish farms and shallow patches off the entrance.
What you will see: the lighthouse, the breakwater, the leading marks, a conspicuous church or hotel.
The lights and depths, in case you are late, and to set a stop depth for the sounder.
Where to berth or anchor, whom to call, and on which VHF channel.
The shelter: which way the harbour or bay is open, and so which wind sends a swell in.

Pilot book · practice harbour (fictional)

Port Kerran

Approach: From the south. Make for Kerran Approach buoy (safe water, LFl10s), then follow the leading lights (Oc 4s) in line on 000° up the buoyed channel, Nos 1 to 4.
Dangers: Mew Rock (dries 1.2 m, isolated danger beacon Fl(2)5s) and a wreck with 4.2 m over it lie west of the approach. The Teeth, off Gull Point to the east, are awash.
Depths: Over 20 m to Nos 3 and 4, then shoaling quickly up the inlet: 5 to 10 m off the quay, drying at the head.
Berths: Visitors stern-to on the south quay with lazy lines. Call the harbour office by phone or VHF before you reach the Approach buoy; in summer a boat comes out to help.
Shelter: Good in northerlies. A southerly sends a swell into the inlet: in a southerly gale go round to Kerran Roads, north of the island.
Facilities: Water and power on the quay. Fuel by arrangement. Shops and tavernas in the village.

A pilot book page for the practice harbour, Port Kerran. Real pilot books add a sketch plan, photographs and the facilities ashore.

Real pages read the same way. Our Central Dalmatia cruising guide describes Milna on Brač as a deep, sheltered inlet, one of the best-protected harbours in the area. In Göcek, our note for Sarsala Bay warns of a fish farm near the entrance. In the British Virgin Islands, Anegada is surrounded by reef: the advice is to go only in good daylight and follow the marked channel to Setting Point.

Planning the approach, leg by leg

Start the plan from a point you can recognise offshore, ideally one with deep water all round it. Then break the way in into legs, each from one mark you can recognise to the next. For each leg note:

The heading, in °M for the steering compass, with the true figure beside it.
The distance and the time it should take, so you know when the next mark is due.
What you expect to see: the next marks, what they look like and where they will appear.
The depth you expect, and the reading that means stop.
The checks: transits, clearing bearings, and where you will stop and decide.

The plan on the practice chart: three legs up the Port Kerran leading line from the Approach buoy, and the western limit for the arrival, a clearing line on the church spire with its danger side hatched. Dotted rings: 4 cables round the wreck and Mew Rock.

Worked example

Leg 1: Kerran Approach buoy to No 1 and No 2

1The track runs up the leading line: 000°T. Variation 3°W, so add 3° for the compass: 003°M.
2On the chart, the Approach buoy to the line joining No 1 and No 2 is 1.6 miles.
3At 5 knots a mile takes 12 minutes: 1.6 × 12 ≈ 19 minutes.
4Expect No 1, a green cone (Fl G 5s), about 10° on the starboard bow, and No 2, a red can (Fl R 5s), about 10° on the port bow: 10° either side of the line, 5.4 cables apart, with the leading lights in line ahead.

Leg 1: 003°M, 1.6 miles, 19 minutes.

Leg	Heading	Distance · time	Expect to see
1 · Approach buoy to Nos 1 and 2	003°M (000°T)	1.6 miles · 19 min	No 1 to starboard, No 2 to port; leading lights in line
2 · Nos 1 and 2 to Nos 3 and 4	003°M (000°T)	6.5 cables · 8 min	No 3 (Fl(2) G 5s) and No 4 (Fl(2) R 5s); Mew Rock beacon abeam (273°M) after 2 cables
3 · Nos 3 and 4 to the harbour	003°M (000°T)	8.5 cables · 10 min	No more buoys; the inlet narrowing, depth falling
Way out	183°M (180°T)	Back to the Approach buoy	Leading lights in line astern

At 5 knots the whole approach, 3.1 miles, takes about 37 minutes: arriving at the Approach buoy at 1530, you are off the harbour at 1607.

InteractiveStep through the plan

Pick each part of the plan to see its leg on the chart and its notes. Tick off each pair of marks as you would on deck.

Leg 1: Kerran Approach buoy to No 1 and No 2

003°M(000°T)1.6 miles · 19 min at 5 knots

Expect to see: No 1 (green cone, Fl G 5s) about 10° on the starboard bow; No 2 (red can, Fl R 5s) about 10° on the port bow
Leading lights (Oc 4s) in line ahead, rear above front
Depth: Over 20 m charted
Check: Decision point here: marks and lights identified? If not, stay in the deep water round the buoy. Tick off No 1 and No 2 at 1549.

2 of 5

The same plan as a skipper might sketch it on a card for the cockpit: legs to scale along the line, not across it. The boxes are ticked on deck with the time.

Leading lines

Many harbours mark the safe way in with a leading line: two marks, or two lights at night, the rear one further away and higher. When they are in line, one directly above the other, you are on the line. The chart and the pilot book give its bearing from seaward; Port Kerran's leading lights (Oc 4s) are in line on 000°T.

You see	You are	Steer
Rear directly above front	On the line	Hold it
Rear open to the left	Left of the line	To starboard
Rear open to the right	Right of the line	To port

Steer towards the rear light (or rear mark) until the two line up again.

InteractiveFollow the leading lights

Move the boat across the channel and closer to the lights, and watch how they open out. Then test yourself: from a hidden position, which way do you steer?

From above: the chart

From the boat: looking at the lights

About 8° across, centred on the front light. Angles to scale; heights exaggerated.

Rear light open to the left

You are left (west) of the line. Alter course to starboard until the rear light is back above the front, then steer to keep them in line.

Rear 0.51° left of front · 1.2 cables west (left) of the line · 2.0 M from the front light

Across the channel: 1.2 cables west (left) of the line

Distance from the front light: 2.0 M

Clearing bearings

Sometimes a danger lies near your way in and no leading line keeps you clear. Then draw a clearing line from a landmark you can see, passing a safe distance clear of the danger, and measure its bearing. While the landmark's bearing stays on the right side of that figure, you are on the safe side of the line. To decide which side: imagine drifting towards the danger. If the landmark's bearing would grow, the limit is not more than (NMT); if it would shrink, it is not less than (NLT).

Worked example

A western limit for the arrival at Port Kerran

1Arriving from the south-west, the wreck (4.2 m over it) and Mew Rock (dries 1.2 m) lie west of the approach. The church spire, above the head of Kerran Bay, is easy to see.
2From the wreck the spire bears 031°T. Take a few degrees off, so the line passes at least 4 cables east of it: 027°T.
3Looking along the line at the spire, the wreck is on your left. Drifting towards it, the spire's bearing would grow, so the limit is NMT.
4For the hand-bearing compass, add the 3°W variation: NMT 030°M.

Church spire NMT 027°T (NMT 030°M): 4.6 cables clear of the wreck and 7.8 cables clear of Mew Rock.

A clearing bearing guards only the dangers it was drawn for. A line drawn for Mew Rock alone (NMT 033°T) passes only 1.8 cables from the wreck, further out. Compare the two below.

InteractiveSafe or not? Check a bearing of the spire

Enter a hand-bearing compass reading of the church spire (°M), or try a random one, and see which side of the clearing line it puts you.

Clearing bearing: church spire NMT 027°T = NMT 030°M on the hand-bearing compass. Enter the spire’s bearing as you read it (°M).

Green: the safe side of the clearing line. Hatched red: the side it keeps you off. Dotted rings: 4 cables round the wreck and Mew Rock.

Picking the gap

From a few miles out, a harbour entrance is often invisible against the land behind it, and a bay looks like every other bay. Pick it out from what the pilot book says you will see: the lighthouse, the end of the breakwater, a conspicuous building, boats going in and out. Read the bearing of the entrance off the plotter and look along it with the hand-bearing compass. Then get onto the approach line well outside, rather than cutting the corner past the rocks off the entrance.

Where the way in is through coral, as at Anegada in the British Virgin Islands, you navigate by the colour of the water: dark blue is deep, turquoise is shallow, and brown or dark patches are coral. You can only read it with the sun high and behind you, so go in the middle of the day, with someone on the bow, and do not trust the electronic chart alone.

InteractiveWhat should you see next?

At each position on the Port Kerran approach, choose what the plan says you should see next. The view ahead appears once you have answered.

Position 1 of 4

Arriving from the south, a mile south of the Approach buoy, heading 003°M.

What should you see when you look ahead? Choose below, then the view appears here.

What should you see next, and where?

The last mile into the marina

Slow down, to five knots or less, so there is time to look and think.
Take the sails down outside the entrance, where there is room to drift while you do it.
Fenders and lines ready on both sides if you do not yet know which side, and brief the crew: who does the stern lines, who takes the lazy line, who fends off.
Decide the stop depth before you go in, and watch the sounder.
Know your way out: here 180°T (183°M) back down the line with the lights astern.

Decision points, and a missing mark

Choose in advance where you will stop and decide. At the Approach buoy: can you identify the marks and the leading lights? If not, stay in the deep water there until you can. Off the entrance: is the berth clear, is the crew ready? If anything does not add up, use the way out.

Buoys drag, sink or get moved, and lights fail. Do not go hunting for a missing mark: stay on the leading line, check the depth and the time, and use a check bearing. Here, Mew Rock beacon bears 273°M from the line 2 cables past No 1 and No 2. If the leading lights cannot be picked out, the church spire stands almost on the line, at about 002°M.

Calling the marina

Call before you arrive, ideally from a few miles out: by phone, or on the VHF working channel the pilot book gives for the marina or harbour office. Channel 16 is for distress, safety and calling, not for arranging a berth. Say:

the boat's name, and that you are a visiting charter yacht;
her length (and beam, for a catamaran);
how many nights you want, and when you will arrive.

They will tell you where to go and which side to have the fenders. In many Mediterranean marinas a marinero comes out in a dinghy, leads you to the berth and hands you the lazy line: a line from a sunken mooring that you take forward to the bow while you go in stern-to and the crew pass the stern lines ashore. Stern-to mooring is a skill of its own: take it slowly, and let the marinero help. In busy towns in July and August the quays fill by mid-afternoon: another reason to arrive early.

Arrive with daylight

Plan every day to arrive with plenty of daylight to spare. Many charter contracts ban sailing at night, and after dark the unlit fishing floats, nets and mooring buoys become very hard to see: in Phang Nga Bay, off Phuket, fishing nets and floats are often unlit. Near the equator the dark comes early and quickly: in the Seychelles it is dark by about half past six all year round.

So aim to be in by mid-afternoon, and if the day is running late, choose the easier harbour: one with a wide, lit entrance and deep water, or a bay you already know. The morning plan from Lesson 1 always has a bolt-hole for this.

Mistake	What goes wrong	The defence
Misidentifying a mark	You take No 4 for No 2, or a mooring buoy for a channel mark, and turn early.	Check colour, shape, topmark, number and light against the plan.
Buoy hopping	Steering from buoy to buoy while the wind sets you sideways onto the shallows.	Stay on the leading line or transit; know the track between marks.
Losing count	You expect the harbour when there is another pair to come.	Tick off each mark with the time.
Heads down	Someone goes below to look at the chart in the middle of the channel.	Do the work before you arrive; hand over the lookout first.
Arriving late	The berth has gone, the light is going and the crew are tired.	Leave early; choose the easier harbour if you are behind.

The Isle of Kerran and Port Kerran are fictional: never use this plan or chart to navigate a real boat. Variation on the practice chart is 3°W; use the compass rose on the chart of your own cruising area.

Key terms

Pilotage: Navigating by eye in confined water, using marks, transits, bearings and the depth.
Pilot book: A guide with a page for each harbour and bay: approach, dangers, lights, berths and shelter.
Leg: One part of the plan, from one recognisable mark to the next.
Leading line: Two marks or lights, the rear one higher, that line up along the safe way in.
Clearing bearing: A bearing of a landmark, not more than or not less than a figure, that keeps you clear of a danger.
Check bearing: A bearing, often of a mark abeam, that tells you how far along a leg you are.
Decision point: A place chosen in advance to confirm all is as planned before you carry on.
Way out: A planned route back to open water if anything does not match the plan.
Lazy line: A line from a sunken mooring, handed up in a marina, that holds the bow when you moor stern-to.

Exercises

Check your understanding. You get a second try at each question, then the worked answer. Score 70% or more to complete the lesson; your progress is saved in this browser.

Where do you find the approach, the dangers off the entrance, the lights and where visitors berth, for a harbour you have never visited?

Leg 1 of the Port Kerran plan is 1.6 miles and you will motor in at 5 knots. How many minutes should it take?

The Port Kerran leading lights are in line on 000°T. Variation is 3°W. What should the steering compass show while you follow them in, on a calm day?

Heading in on the leading line, you see the rear light open to the left of the front light. Which way do you steer?

A little later the rear light has opened to the right of the front light. Now what?

Arriving from the south-west, your clearing bearing is church spire NMT 030°M. The hand-bearing compass gives the spire 034°M. Are you safe?

On the leading line, with the lights in line, Mew Rock beacon bears 273°M, due west once converted. Tap your position.

On leg 2 of the plan, No 3 and No 4 are due but you cannot see No 4. What do you do?

The pilot book says the way into a Caribbean anchorage is through a gap in the reef. When is the best time to go in?

How do you call a marina to ask for a berth?

It is 1700 and you are still 15 miles from tonight's harbour, a narrow rocky inlet. What is the sensible plan?

0 of 11 answered · 0 correct

Pilotage practice

Four fresh questions each time: two leading-light views, a leg time and a clearing-bearing check.