End-User License Agreement (EULA) for TideDeck
Last Updated: July 20, 2026
Please read this End-User License Agreement ("EULA") carefully before using the TideDeck mobile application ("the Application") operated by Maritime Master Limited, formerly known as Bottle Top Studios Ltd, a company registered in England and Wales under company number 15339200 ("Maritime Master", "us", "we", or "our").
By downloading or using the Application, you are agreeing to be bound by the terms and conditions of this Agreement. If you do not agree to the terms of this Agreement, do not download or use the Application.
1. License Grant
Maritime Master grants you a revocable, non-exclusive, non-transferable, limited license to download, install, and use the Application on devices that you own or control, solely for your personal, non-commercial planning and general interest purposes, strictly in accordance with the terms of this Agreement.
2. Restrictions
You agree not to, and you will not permit others to: a. License, sell, rent, lease, assign, distribute, transmit, host, outsource, disclose, or otherwise commercially exploit the Application or make the Application available to any third party. b. Modify, make derivative works of, disassemble, decrypt, reverse compile, or reverse engineer any part of the Application. c. Remove, alter, or obscure any proprietary notice (including any notice of copyright, trademark, or third-party data attribution) of Maritime Master or its affiliates, partners, or licensors of the Application. d. Extract, scrape, redistribute, or resell the tide predictions, harmonic constants, station data, or model data contained in or generated by the Application. e. Use the Application, or any output of the Application, for navigation, for any commercial maritime operation, or as an input to any other navigational product or service.
3. THE MOST IMPORTANT THING TO UNDERSTAND: HEIGHTS ARE NOT DEPTHS
THE APPLICATION PREDICTS THE HEIGHT OF THE TIDE ABOVE A REFERENCE LEVEL, KNOWN AS A DATUM. IT DOES NOT KNOW, MEASURE, OR ESTIMATE THE DEPTH OF THE WATER, THE LEVEL OF THE SEABED, OR THE DRYING HEIGHT OF ANY SILL, BAR, BANK, SLIPWAY, CAUSEWAY, OR MOORING.
A predicted height of two metres does not mean there will be two metres of water beneath you. It means the surface of the sea is predicted to be two metres above the datum used for that location. To know the depth at a place, you must add the predicted tide height to the charted sounding for that exact spot, taken from an official, current chart that uses the same datum. The Application does not hold charted soundings or drying heights, does not ask you for them, and cannot perform that calculation for you.
Any clearance, under-keel, or minimum-water figure shown in the Application is derived only from predicted tide height, your stated draught, and your stated clearance. It does not account for the level of the ground beneath you. Over any feature that dries, the figure will overstate the water available, by the full drying height of that feature. You must never rely on it to decide whether you can float, pass, launch, moor, or enter anywhere.
4. Not for Navigation
THE APPLICATION IS PROVIDED FOR GENERAL PLANNING AND INTEREST ONLY AND MUST NOT BE USED FOR NAVIGATION, PASSAGE PLANNING, PILOTAGE, OR ANY OPERATIONAL OR SAFETY-CRITICAL DECISION.
The Application is not an official tide table, is not a nautical publication, is not approved, certified, or endorsed by any hydrographic office, harbour authority, government agency, or maritime administration, and does not meet any carriage requirement. For navigation you must use official tide tables, official charts, and the directions of the relevant harbour or port authority, all current and correct for your location and date.
5. How the Predictions Are Produced, and Their Limits
a. Two Very Different Kinds of Prediction: For a limited number of locations, the Application computes tides from published harmonic constants derived from measured observations at that gauge. For everywhere else, it computes tides from a global or regional ocean tide model. Modelled predictions are approximations for a broad area of ocean, not measurements of your location, and they can differ materially from the real tide in both height and time. The Application labels which kind of prediction you are viewing. You must check that label before relying on anything.
b. Distance From the Data: Where your chosen point is not surrounded by ocean cells in the model, the Application may use constants taken from the nearest available ocean cell, which can lie a very considerable distance away, on the order of a hundred kilometres or more. Such a prediction may bear little relation to the tide where you actually are.
c. Datum Differences: Different data sources use different reference levels. Predictions derived from gauge records are expressed relative to the mean level of that gauge and imply no official chart datum whatsoever. Modelled predictions use a datum the Application derives for itself. These levels are not interchangeable with the datum printed on your chart, and heights from the Application therefore cannot safely be added to charted soundings unless the datums are known to match.
d. No Weather Effects: The Application computes the astronomical tide only. It does not model, include, or correct for storm surge, barometric pressure, wind set-up or set-down, seiche, river discharge, flood water, or any other meteorological or hydrological effect. Real water levels regularly depart from astronomical predictions, sometimes by a large margin and sometimes with little warning. In surge conditions the real level may be far higher or far lower than anything the Application shows.
e. No Tidal Streams or Currents: The Application does not predict tidal streams, current set or drift, rate, or the timing of slack water. Nothing in the Application, including any educational content about the behaviour of the tide, may be used to plan around currents or to time a dive, a passage, or any activity affected by moving water.
f. Coverage Varies by Country: Measured-station coverage is not global and is materially better in some countries than others. In particular, no official hydrographic office constants are bundled for the United Kingdom, so no United Kingdom location has an official chart-datum prediction in the Application. This matters especially in waters with large tidal ranges, drying harbours, and tidal causeways.
g. Local Effects: The Application cannot account for local phenomena such as harbour works, sluices, barrages, lock operation, dredging, silting, shoaling, seasonal changes, or any local correction published by a harbour authority.
6. Planning Tools, Activity Ratings, and Alerts
a. Ratings and Windows Are Suggestions Only: Any activity rating, suitability score, decision card, best-day suggestion, or planning window in the Application is a convenience generated from predicted tide height alone. It does not assess, and cannot assess, sea state, swell, waves, currents, wind, weather, visibility, water quality, water temperature, pollution, marine life, ground conditions, access, local byelaws, lifeguard cover, your equipment, or your ability. A favourable rating is not advice that an activity is safe.
b. Tidal Cut-off: Rising water strands and drowns people on beaches, sandbars, rock ledges, causeways, and coastal paths every year. Predicted times and heights are not a safety margin. Always leave a wide margin, always know your escape route, always check local signage and official safety information, and never rely on the Application to tell you how long you can stay.
c. Notifications: Any alert or notification the Application delivers is generated from a prediction that may have been made some time earlier, and arrives without the context, labelling, and warnings shown inside the Application. Notifications are reminders only and must never be acted on as a safety instruction.
d. Safety Margins: Any safety margin or allowance setting in the Application is a user preference applied to a prediction. It is not a guarantee, it does not make a prediction conservative, and no setting can compensate for the limits described in Sections 3 and 5.
7. Weather, Live Data, and Connectivity
Tide predictions are computed on your device. Other features, including weather information, live observations, map search, satellite imagery, and synchronisation between your devices, require an internet connection and depend on third-party services that may be unavailable, delayed, incomplete, or inaccurate. Weather information is provided by third parties, is a forecast rather than a fact, and is subject to the terms and attribution requirements of those providers. We do not control and are not responsible for third-party data.
8. Subscriptions and Purchases
The Application offers optional paid access ("TideDeck Pro"), available as an auto-renewing annual subscription and as a one-time lifetime purchase. All purchases are processed by Apple through your Apple Account; we do not receive or store your payment details. Prices are displayed in the App Store before you confirm. An auto-renewing subscription renews automatically and your Apple Account is charged for the next period unless you cancel at least 24 hours before the end of the current period. You can manage or cancel a subscription at any time in your device's App Store subscription settings; cancellation takes effect at the end of the current billing period. A lifetime purchase does not renew. Previous purchases may be restored on eligible devices. Refunds are handled by Apple in accordance with the App Store terms. Paid features are licensed, not sold, to you, and remain subject to this Agreement, including every limitation and disclaimer in it. Paying does not make a prediction more accurate or more suitable for navigation.
9. Disclaimer of Warranties
The Application is provided to you "AS IS" and "AS AVAILABLE" and with all faults and defects without warranty of any kind. To the maximum extent permitted under applicable law, Maritime Master, on its own behalf and on behalf of its affiliates and its and their respective licensors and service providers, expressly disclaims all warranties, whether express, implied, statutory, or otherwise, with respect to the Application, including all implied warranties of merchantability, fitness for a particular purpose, title, and non-infringement, and warranties that may arise out of course of dealing, course of performance, usage, or trade practice. Without limitation to the foregoing, Maritime Master provides no warranty or undertaking, and makes no representation of any kind, that the Application will meet your requirements, achieve any intended results, be accurate, be compatible or work with any other software, applications, systems, or services, operate without interruption, meet any performance or reliability standards, or be error-free, or that any errors or defects can or will be corrected.
10. Limitation of Liability
To the maximum extent permitted by applicable law, in no event shall Maritime Master or its suppliers be liable for any special, incidental, indirect, or consequential damages whatsoever (including, but not limited to, damages for loss of profits, for loss of data or other information, for business interruption, for personal injury, for loss of privacy, for grounding, stranding, collision, capsize, flooding, or other marine or coastal incident, or for any other loss arising out of or in any way related to the use of or inability to use the Application, third-party software, third-party data and/or third-party hardware used with the Application, or otherwise in connection with any provision of this Agreement), even if Maritime Master or any supplier has been advised of the possibility of such damages and even if the remedy fails of its essential purpose. Nothing in this Agreement excludes or limits liability for death or personal injury caused by negligence, for fraud or fraudulent misrepresentation, or for any other liability that cannot be excluded or limited under applicable law.
11. Assumption of Risk and Indemnity
You acknowledge that activities on, in, and beside the water are inherently dangerous, that tidal water strands and drowns people, and that relying on a planning application in place of official publications, proper training, local knowledge, and your own judgement could result in serious injury, death, or loss of or damage to property. Any use of the Application contrary to this Agreement is entirely at your own risk. To the maximum extent permitted by applicable law, you agree to indemnify and hold harmless Maritime Master Limited, its officers, employees, and agents from and against any claims, liabilities, damages, losses, and expenses (including reasonable legal fees) arising out of or in connection with your use of the Application in breach of this Agreement, including any use of the Application or its output for navigation or operational decision-making.
12. Your Data and Privacy
The Application does not require an account. If you grant location access, your device position is used on your device to sort nearby locations and is not transmitted to us. Where you use features that depend on third-party services, such as weather, live observations, or map search, the coordinates of the location you are viewing and standard connection information are sent to those providers in order to return a result. Your preferences, saved places, and notes are stored on your device and, if you enable it, synchronised through your own private iCloud account, which we cannot access. Our processing of personal data is described in our Privacy Policy at https://www.themaritimemaster.com/policies/privacy-policy, which is incorporated into this Agreement by reference.
13. Third-Party Data and Attribution
The Application incorporates data from third parties, including public-domain harmonic constants and observations published by government agencies, openly licensed global and regional ocean tide models, openly licensed geographic and place data, and weather data provided by third-party services. Those datasets remain the property of their respective owners and are used under their own licences. The attributions and licence notices shown within the Application form part of the terms on which you may use it, and you must not remove, obscure, or separate them from the data they describe. Credit to any agency or provider does not imply that the agency or provider has reviewed, approved, or endorsed the Application.
14. Intellectual Property
The Application, including its software, interface, design, original text, and all associated copyrights, trademarks, and other intellectual property rights, is and shall remain the sole and exclusive property of Maritime Master Limited, save for third-party components and data licensed as described in Section 13.
15. Apple App Store
You acknowledge that this Agreement is between you and Maritime Master Limited only, and not with Apple Inc. ("Apple"). Apple is not responsible for the Application or its content and has no obligation to provide any maintenance or support services for the Application. In the event of any failure of the Application to conform to an applicable warranty, you may notify Apple and Apple will refund any purchase price you paid for the Application; to the maximum extent permitted by applicable law, Apple has no other warranty obligation with respect to the Application. Apple and its subsidiaries are third-party beneficiaries of this Agreement and may enforce it against you. You represent that you are not located in a country subject to a relevant government embargo and that you are not on any applicable government list of prohibited or restricted parties.
16. Termination
This Agreement will terminate immediately, without prior notice from Maritime Master, in the event that you fail to comply with any provision of this Agreement. You may also terminate this Agreement by deleting the Application and all copies thereof from your devices. Upon termination you shall cease all use of the Application and destroy all copies of it. Termination does not entitle you to any refund except as required by law or by Apple's policies, and the provisions of this Agreement which by their nature should survive termination shall survive, including Sections 3, 4, 5, 6, 9, 10, and 11.
17. Governing Law
This Agreement, and any dispute or claim arising out of or in connection with it, shall be governed by and construed in accordance with the laws of England and Wales. Your use of the Application may also be subject to other local, state, national, or international laws. Nothing in this Agreement affects any mandatory consumer rights available to you under the laws of your country of residence.
18. Severability
If any provision of this Agreement is held to be unenforceable or invalid, such provision will be changed and interpreted to accomplish the objectives of such provision to the greatest extent possible under applicable law, and the remaining provisions will continue in full force and effect.
19. Changes to This Agreement
We may update this Agreement from time to time. The "Last Updated" date at the top of this page indicates when it was last revised. Your continued use of the Application after an updated Agreement takes effect constitutes your acceptance of the revised terms.
20. Entire Agreement
This Agreement constitutes the entire agreement between you and Maritime Master Limited regarding your use of the Application and supersedes all prior and contemporaneous written or oral agreements between you and Maritime Master Limited, including any agreement made with Bottle Top Studios Ltd in respect of the Application.
21. Contact Information
If you have any questions about this Agreement, please contact us via the Contact page at https://www.themaritimemaster.com/pages/contact.