Coastal planning worldwide

Passage planner.

Live model conditions for global harbours, with verified local detail where available.

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Wind
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Significant waves
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Weather
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Sea temperature
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Loading trend…Needs two model values exactly three hours apart

MODEL OUTLOOKLoading wind, weather and marine forecasts independently.

Hourly detail

01 / Make a plan

Where are you heading?

Saved on this device
From Guernsey
Straight-line distance6.9 nm
Running time estimate23 min

A distance estimate; allow for your charted route and tidal stream.

St Peter PortSark
PASSAGE OVERVIEW

Straight-line overview, not a navigational route.

At your departure port

Choose a time within the available forecast to see conditions.

Marina clearance & departure comparisons

Marina clearance

1.2 m draught + 0.5 m margin = 1.70 m required water depth.

Digimap predictions · QE2

Choose a departure date and time.

Estimated under-keel clearance · gates fully downChoose departure time

Predictions do not confirm the live gate position or actual depth.

QE2 has dropping gates. Follow the entrance lights and check the marina gauge before crossing. Its fixed board reads above the raised gate; the lower sill is available only with the gates fully down. Neap tides can shorten access.

Tide predictions: Digimap · underlying data © Crown Copyright / UKHO.

Compare departure hours

The 24 hours after your selected departure, ranked by wind, waves and rain at the departure port.

No complete forecast hours in this window. Choose a nearer departure or check the official forecast.

Selecting an hour updates departure. Streams change through time and along the passage; this comparison does not assess the whole route or tidal gates.

Saved passages 0

Save a passage above to keep it here for next time.

Wind, waves & rain · UTC

The hours ahead

Forecast at St Peter Port; conditions along your route will vary.

Comparison thresholds: raised at gusts ≥20 kn, waves ≥1.2 m or rain ≥60%; high at gusts ≥28 kn, waves ≥2 m or thunderstorms. These are not vessel-specific departure limits.

Check the official forecast

Beyond the forecast

Sea life & time on the water

Local observations, water conditions, coastal stops and the bigger boats around you.

Pins show where animals were reported on the recorded date. Animals move; these are historical observations.

Importing observations…

Loading the published records and their observation dates.

Checking source…

Before you cast off

Five checks. Every passage.

Progress is saved here. Reset this checklist before each new departure.

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Guernsey passage briefs

Know your crossing

Decision prompts only—not waypoints or turn-by-turn pilotage. Recalculate for your boat, crew, weather and the day’s tidal stream.

Guernsey → Alderney

About 21nm straight-line

Advanced

Powerful tidal streams and very small timing margins.

  • Choose the route and tidal gate from a current pilot/chart
  • Check wind against tide in the Swinge and Alderney Race
  • Confirm Braye conditions and a realistic abort plan
Alderney harbour guidance

Guernsey → Jersey

About 23nm straight-line

Intermediate

Strong streams, busy approaches and a tidally constrained arrival.

  • Check the full passage against the day’s tidal predictions
  • Use approved St Helier approaches and monitor VTS Ch 14
  • Watch for rougher water when wind opposes the stream
Jersey Coastguard guidance

Guernsey → Sark

About 7nm straight-line

Intermediate

Short crossing, but exposed moorings and strong local streams.

  • Choose the lee-side visitor field for the forecast wind
  • Yellow visitor buoys are first come, first served
  • Creux dries; Maseline is drop-off only when operationally clear
Sark visitor guidance
Guernsey → Alderney: ReadyBoatGo deliberately does not give a generic “leave at X hours” rule. The safe gate changes with route, boat speed, wind, sea state and spring/neap cycle—use current charted tidal streams and local pilotage advice.

Visitor moorings

Sark & Alderney mooring finder

Visitor fields and your own observations, saved on this device. Contact the harbour for current availability.

Approximate visitor fields. Use current charts and harbour instructions for buoy positions.

Havre Gosselin

Yellow visitor buoys · west coast

No observation

Record spaces you can see

Official information

Gréve de la Ville

Yellow visitor buoys · east coast

No observation

Record spaces you can see

Official information

Check latest public AIS

Confirm before arriving

Use current charts and contact the harbour. Public AIS does not establish whether a visitor buoy is free.

Harbour view

Nearby webcams

Check visibility and activity before departure.

Availability is controlled by each webcam operator and may change during maintenance.

Marina fuel

Fuel prices at St Peter Port

Supplier prices and your own pump-price notes.

Checking Boatworks…
Boatworks prices & pontoon access

Diesel

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Petrol

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Compare recorded fuel prices

Price differences only: grades and duty bases can differ. Detour fuel is not deducted.

Diesel

Cowes, Isle of Wight · 92nm

£1.68/L · 9 Sept 2026

Cowes Harbour

Add this port's price
to calculate

Petrol

Cowes, Isle of Wight · 92nm

£1.88/L · 9 Sept 2026

Cowes Harbour

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to calculate

Save your own pump-price note

£

Boatworks prices come from its supplier page, checked hourly while this page is open. Cowes prices are supplier-published 60/40 diesel and E10 petrol. Elsewhere, save a dated note only after checking the pump. Always confirm price, grade, duty basis and pontoon access before fuelling.