Tidal Harbours

Lock, gate and sill times

Free · In‑App Purchases · Designed for iPad. Not verified for macOS.

Lock, gate and sill times read at a glance, from the Channel and the Atlantic to Belgium and the Netherlands. Depth under the keel worked out, tides computed on board. Make your way through French harbour gates and locks the easy way. Tidal Harbours lists every lock, gate, sill and drying harbour of the French Channel, the Atlantic coast, Belgium, Netherlands and the Channel Islands. For a lock or a gate harbour, it shows you the times for any day you like, easily. For a sill or a drying harbour, it shows when you can pass, from your boat's draught and from the heights of water computed from the local tide. WHAT IT DOES •Today's access windows, harbour by harbour , to the minute, for 187 harbours with a lock, gate or sill — read at a glance on your watch or on your phone's widget, without opening the app • The depth of water over the sill, worked out from YOUR draught and YOUR safety margin • The water under the keel, worked out from your draught, the tide, the day, the hour and the depth of the bottom • How long you stay aground, and when you float again • Tide tables with no limit in time for 200 reference points: high and low water, coefficients, ranges • How long you have left under the keel at anchor, and when the boat will touch,set two draughts and let each anchorage remember which one applies • Every tidal harbour on the chart, with its openings at the hour you choose • The widget and the watch refresh on their own, so the next window is there when you look WHERE THE FIGURES COME FROM Every harbour was surveyed one by one. Sill levels come from the harbour authority or were checked against Nautical charts. Lock times are copied from the calendars the harbours publish, and they are renewed every year. Where no times are published, the harbour's own rule is applied. The tide is worked out on the device, from a harmonic analysis over 145 constituents. Every tidal reference was computed from the official records of the French tide gauges and checked against the official tide tables of the naval hydrographic service over three full years. Our figures are verified by comparison with past predictions from the official tide tables. The small differences that remain are not hidden. EVERYTHING IS WORKED OUT ON BOARD No tide is ever downloaded. The app works with no signal at all, which is the only thing that matters at anchor. It creates no account, asks for no login, sets no tracker and carries no advertising library. It does know how to fetch and update lock calendars or ports tide when they change. CAUTION Tidal Harbours is an aid to planning, not a nautical document. A calculation is not a guarantee: a lock can be shut, a rule can change mid-year, a gale can shift high water by half an hour. Always check with the official tide tables and the harbour office before you present yourself at a lock, a gate or a sill. Every harbour page carries its telephone number. Our tide calculations claim no certainty. Know how to check them. THE SUBSCRIPTION Three days' trial, then £7.99 a year. When it expires the app stays open: you keep the chart, the harbour pages, the levels and the numbers, but it no longer announces times or tides. Published times are updated harbour by harbour. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://portsamaree.github.io/

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Version 2.0 SAVE YOUR ANCHORAGES Name a spot, keep its sounding and the tide it is worked out from, and find it again next season. Your anchorages now travel with your iCloud account: they survive a reinstall and follow you from iPhone to iPad. SOUNDED ON THE SPOT Read the depth under your boat, enter it, and the app works back to the level of the bottom referred to chart datum, from the tide at that very minute. What you measured once holds for every tide after. KEEL OR CENTREBOARD Set two draughts and let each anchorage remember which one applies. A drying berth is taken with the board up; the pontoon next door is not. DRYING HARBOUR LEVELS ARE YOURS TO ADJUST The bottom silts up and differs from berth to berth. Ours comes from the harbour's own document; yours holds for your berth, now up to five metres either way. ALSO • Six harbours added, including Pornic La Noëveillard, Gravelines and Molène

Version 2.0

The developer, vincent terrisse, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

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    Information

    Seller
    vincent terrisse
    Size
    32.4 MB
    Category
    Navigation
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • iPad
      Requires iPadOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    • Apple Watch
      Requires watchOS 10.0 or later.
    Languages
    English and French
    Age Rating
    4+
    In-App Purchases
    Yes
    Copyright
    © 2026 Vincent Terrisse
  • Privacy Policy

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