Terms of Use

Sirena Seafarer · Effective 30 October 2026 (version 4.0.6 and later) · Replaces the version of 24 October 2026

1. Agreement

These terms are a binding agreement between you and the provider named under "Who we are" at the end of this page ("Sirena", "we"). By installing or using the Sirena Seafarer app or sirenaclub.io you accept them. If you do not accept them, do not use the service. If you use Sirena on behalf of someone else (an owner, a charter company, a club), you confirm you are authorised to bind them.

2. The service

Sirena provides: self-hosted vector charts rendered from OpenStreetMap data, GPS instruments (position, SOG, COG, heading), track recording, waypoints and routes, offline chart downloads, optional live position sharing with other users ("presence" and "fleet"), optional overlays (our own seamark files, AIS, weather), regatta courses you can draw and share, a race start timer, an anchor watch, a distress assist screen, an optional game on the Play chart with Game Center achievements, and optional Premium charts (Light, Satellite Mapbox, OSM Day and Night, TSS Day and Night, NOAA US chart data). Features may change, be added or be withdrawn at any time.

3. Safety and assumption of risk

• Not navigation equipment. Sirena Seafarer is not an ECDIS or ECS, is not type-approved under IEC 61174 or IEC 62376 or any other standard, does not meet SOLAS chapter V carriage requirements, and is not an approved anchor alarm, AIS display or distress system. Do not use it as the primary means of navigation on any vessel.
• Boating is inherently dangerous. Weather, sea state, traffic, equipment failure and human error can cause injury, death and loss of property. You assume all risk of using Sirena on the water.
• Sirena depends on your phone: GPS accuracy, battery, temperature, water damage and cellular coverage are outside our control. Expect the app, the phone or connectivity to fail at the worst possible moment, and plan accordingly.
• The SOS screen is a convenience that displays your position and helps you place a phone call. It does not transmit a distress signal, does not alert rescue services by itself, and is not a substitute for VHF/DSC radio, EPIRB, PLB, flares or any required distress equipment.
• Positions of other boats (presence, fleet) are self-reported, delayed and may be stale by an hour or more. They must never be used for collision avoidance, search and rescue, or any safety-critical decision.
• Offline charts are snapshots. They can be outdated the moment you download them. Keeping them current is your responsibility. The free offline area covers only the waters around where the app last had a position and signal; outside it, without signal, only a rough outline of the land is shown.
• The Apple Watch app mirrors the iPhone. It may lag or disconnect; the regatta clock on the watch keeps counting on its own but is not an official start signal.
• Weather or signal-coverage information, where shown, is indicative only.
• The anchor watch relies on the phone's GPS, battery, background execution and sound settings. It may raise false alarms, or none at all, and it is not a substitute for a proper anchor watch kept by a person.
• The regatta start timer is computed on your phone and may drift. It is not an official start signal; follow the race committee.
• The SOS screen is not DSC and does not contact any coastguard or rescue service automatically.

4. Accounts

You must be at least 16 to create an account (or the higher age your law requires to operate a vessel or consent to data processing). Provide accurate information. You are responsible for all activity under your account and for keeping your device secure. Email accounts are bound to a device credential in the iOS Keychain; Sign in with Apple works across your own devices. We may suspend or terminate accounts that violate these terms.

AIS traffic is an aid, never a collision-avoidance system. It shows only vessels that carry an AIS transponder and choose to broadcast. Most small pleasure craft carry none and will not appear at all. Positions arrive with a delay, may be wrong, and the feed comes from a free public service that can stop without notice. An empty screen does not mean empty water. Nothing here replaces a proper lookout, radar, or the COLREGs.

Weather is a forecast, not an observation. The wind and sea data is a computed model, not a measurement, and it is not an official marine forecast or warning service. Always obtain official forecasts and warnings for your area before you sail.

Traffic separation schemes shown in the app are not an official chart. They are derived from IMO COLREG circulars, NOAA and OpenStreetMap data, may be out of date, and must not be used for navigation or routeing decisions. Use the official charts and notices to mariners.

The coverage line is geometry, not a measurement. It draws a fixed distance from the coast to show where mobile signal plausibly ends. Your phone cannot survey coverage ahead of you. Do not plan communications on it.

5. Position sharing and the fleet

• Sharing is off by default. Turning it on is your choice and can be reverted at any time.
• With sharing set to Everyone, your boat appears anonymously to other users; only your accepted fleet sees your identity. With Fleet only, only your fleet sees you. While sharing is off you do not see other boats (reciprocity).
• You may not use presence or fleet data to stalk, harass, follow or intercept any person or vessel; to compile datasets about other users; or for any law-enforcement, surveillance or commercial-tracking purpose. We may terminate accounts that do.
• Fleet connections are mutual: both sides accept, either side can sever the link at any time, and severing is immediate in both directions.
• You may invite by QR code, share link, or a phone number the other captain saved on their profile. We look up a hash of that number. We do not read your address book.
• Do not share an account or publish positions of a vessel without the authority of its skipper.

6. Acceptable use

You agree not to: (a) scrape, harvest or bulk-download our APIs, tiles or user data; (b) probe, overload, disrupt or circumvent security or rate limits; (c) reverse engineer, resell, sublicense or provide the service to third parties as your own; (d) upload malicious code or unlawful content; (e) impersonate others or misrepresent a vessel identity (including MMSI or call sign); (f) use Sirena where or in a way prohibited by law, including sanctions and export laws. We may throttle, suspend or terminate access to protect the service and its users.

7. Sirena Premium

Premium is sold by Apple in three forms, and the offline world chart as a separate one-time purchase. Prices shown are for the United States; your territory may show a different amount, and the price displayed in the App Store at the moment you buy is the one that applies.

• Sirena Premium Annual, an auto-renewable subscription at $149.99 per year. It is shareable with your Apple Family group, so one subscription entitles up to six members, each through their own Sirena account.
• Sirena Premium Monthly, an auto-renewable subscription at $14.99 per month, for a single account. It is not shareable with a Family group.
• World Chart Offline, a one-time purchase of $49.99 that downloads the whole world's Sirena Seafarer chart (about 1.1 GB) to your device for offline use. It does not renew, there is nothing to cancel, it is for a single Apple Account and is not shareable with a Family group. It is sold by Apple and can be restored on your devices from the app. Without it, the app saves the waters around your current position (about 40 km) for offline use, free. The download uses Apple's Background Assets, which needs iOS 26.4 or later, so the world chart is offered only on iOS 26.4 and later.
• Welcome week: devices that started the app before version 4.0.5 got the paid features for 7 days at no charge, without any purchase or payment details. A week already running ends on its own; nothing renews and nothing is charged. New devices get the free trial of the monthly plan instead (see Free trial below).
• The free chart: the Sirena Seafarer chart shows the world's coastline and, in full detail, about 40 km around your current position. Your own position, the anchor watch, the distress screen and AIS are never limited.
• Sirena Founding Seat, a one-time purchase of $249.99 that unlocks the same paid features for a single account for the lifetime of the app (if we discontinue the service, we will give at least 90 days' notice). It does not renew, there is nothing to cancel, and it is not shareable with a Family group. We may withdraw it from sale at any time; that does not affect anyone who already bought it.

• Introductory offer. The annual plan currently carries an Apple introductory offer: your first year costs $69.99, after which it renews at the standard $149.99. The App Store shows both figures before you buy. We may end the offer at any time, which does not affect anyone already in their introductory year. This is an Apple offer, not a price locked to you personally: when your introductory year ends, the standard price applies.
• Subscriptions renew automatically unless cancelled at least 24 hours before the current period ends. Payment is charged to your Apple Account at confirmation of purchase, and renewals are charged within the 24 hours before the period ends. Manage or cancel in iOS Settings → Apple Account → Subscriptions. Refunds are handled by Apple under Apple's terms.
• Prices may change for future periods. Apple notifies you and, where required, asks for your consent before charging a higher amount.
• Free trial. The monthly plan ($14.99 a month) starts with a 7-day free trial through the App Store. You confirm the subscription with Apple on day 1 and nothing is charged during the 7 days. Unless you cancel at least 24 hours before the trial ends, it converts automatically to the monthly plan and $14.99 is charged to your Apple Account, then every month until you cancel. If you cancel during the trial, nothing is charged and the free features remain. Apple decides who is eligible: the trial is given once per Apple Account in this subscription group.
• Purchases are sold by Apple as merchant of record. Refunds, including any statutory 14-day withdrawal right, are handled by Apple (reportaproblem.apple.com) under Apple's Media Services Terms.
• Free features, trials and promotional access, including the free trial and the introductory offer, may be modified or withdrawn at any time and create no entitlement. Withdrawing them does not entitle you to a refund of a paid subscription or of a founding seat, which are unaffected.
• Family Sharing applies to the annual subscription only. Where you enable it, each family member's own Sirena account is entitled to the paid features. Accounts remain separate: sharing a subscription does not share position data, fleets or any other content between members. Apple controls who is in your family group and you manage that in iOS Settings.
• What Premium unlocks: the Light chart, Satellite Mapbox, OSM Day and Night, TSS Day and Night, and NOAA US chart data. Free for everyone, with or without a subscription: the Sirena Seafarer chart and its offline copy, Satellite Sirena, the Play chart, AIS, weather, track, waypoints, routes, regattas including creating a course, the signal line, anchor watch, the SOS screen, position sharing and the fleet.
• Sirena.Club: a Sirena Premium purchase you made yourself also opens a Silver seat in Sirena.Club, our separate members' app, where Sirena.Club is available (it is not offered in the European Union): while your annual or monthly subscription is active, and for as long as the club operates for the founding seat. A purchase shared with you through Family Sharing does not open the club. A Sirena.Club membership you bought yourself includes Sirena Premium. The club is governed by its own terms at sirena.club/terms.

Sirena Logbook Pro. A Sirena Premium subscription or founding seat you bought yourself (not one shared through Family Sharing) also includes Logbook Pro in our separate Sirena Logbook app, where Sirena.Club is available (it is not offered in the European Union), through the link in Sirena.Club. Logbook Pro is also sold in Sirena Logbook itself.

8. Referral programme

You can invite other sailors to Sirena Seafarer with your personal invite link, QR code or invite code (shown in the app under Account). You get one free month for every friend whose first paid period (monthly or annual) goes through.

• Who qualifies. A friend qualifies when they open your link or enter your code and then sign in to Sirena Seafarer with a new account, or with an existing account that has never bought Sirena Premium and was not invited by someone else. The first invite a friend accepts is the one that counts, and it cannot be changed later. You cannot invite yourself or another account of your own.
• When the reward is granted. You get one free month of Sirena Premium for every friend whose first paid period (monthly or annual) goes through. A free trial or any other free period does not count. Each friend can earn you one free month, once. Nothing is granted if the payment is refunded or reversed before the month is granted, for purchases made through Family Sharing, for purchases that began before the invite was accepted, or for test purchases.
• No limit. There is no cap on how many free months you can earn.
• How free months are applied. Free months are kept for you and shown in the app under Account. You apply them one at a time from the app, through the App Store, as an Apple promotional offer on your Sirena Premium subscription: Apple shows the free month and its terms before you confirm, and Apple's terms for subscription offers apply. Apple makes these offers available to current and former subscribers only, so if you have never subscribed, your free months are kept and can be used once you subscribe. A month you start to apply but do not confirm is returned to you.
• No cash value. Rewards have no cash value, cannot be exchanged for money, sold or transferred, and are not a payment for your invitation. Your friend pays the normal App Store price; the referral programme does not change what they are charged.
• Fair use. We may withhold or cancel rewards obtained through fake, duplicate or self-created accounts, bulk messaging, or any other abuse of the programme. You must not spam, run paid advertising on the Sirena name, or misrepresent the offer. A free month may be withdrawn if the qualifying payment is later refunded. Apple's eligibility rules for promotional offers apply.
• Changes. We may change or end the referral programme at any time. Free months you earned before a change or the end of the programme stay yours to apply under Apple's terms.

9. Your content

Waypoints, routes, tracks, names and other content you create remain yours. You grant us the limited license needed to store and display that content to you and, where you enable sharing, to the users you chose, and to operate backups. We may remove content that violates these terms or the law.

You may not use names, boat names, course titles or other content that is unlawful, harassing, hateful, sexual, or that impersonates another person or vessel. We have zero tolerance for objectionable content or abusive users: report either to [email protected] and we aim to act within 24 hours, including removing content and suspending accounts. You can remove any fleet member at any time, which ends all contact between you in the app.

10. Race courses

You can draw a race course and share it as a link. Anyone with that link can open the course and sail it without a subscription.

A course you share is your responsibility. Do not place marks where sailing to them is unsafe, and do not organise a race that conflicts with traffic separation schemes, restricted areas, local rules or the COLREGs. Timing is computed on each participant's own phone from its own GPS and is not an official result: it is not race-committee timing, it does not apply the Racing Rules of Sailing, and it settles nothing. Anyone running a real competition must keep their own official record.

You remain responsible for the safety of your own vessel and crew at all times, whether or not you are racing.

11. Map data and third-party licenses

Base charts contain data © OpenStreetMap contributors, available under the Open Database License (ODbL); rendering © Sirena. Seamark data is derived from OpenSeaMap and hosted by us: the app does not fetch tiles from OpenSeaMap's servers. NOAA chart objects are derived from US government ENC data (public domain) and are subject to NOAA's own terms and availability. Satellite imagery on the Satellite Sirena layer contains modified Copernicus Sentinel data (ESA). The Satellite Mapbox layer (imagery © Mapbox © Maxar) is served by Mapbox and is additionally subject to Mapbox's terms. The offline Sirena Seafarer chart is delivered through Apple-hosted Background Assets. The wind and sea forecast comes from MET Norway (the Norwegian Meteorological Institute) under CC BY 4.0 and the Norwegian Licence for Open Government Data (NLOD 2.0). Wave coverage from that source is Northern and Western Europe; outside that area the wind forecast is still shown and wave fields may be empty. AIS traffic comes from aisstream.io and AISHub under their terms and is provided without any service guarantee: both are public feeds with no availability commitment and may stop at any time. Your use of third-party data is additionally subject to those projects' licenses. Attribution notices in the app must not be removed.

11a. Sea Treasure, Game Center and virtual items

The game is optional and appears only on the Play chart. Never alter course, speed or watchkeeping to collect an item: items may appear in places unsafe for your vessel, and you alone decide where you go. Achievements and leaderboards never reward speed or distance offshore. Points, badges and other virtual items have no cash value, cannot be exchanged for money or transferred, may be changed or reset, and are a licence, not property. Game Center names and scores are handled by Apple under Apple's terms.

12. Intellectual property

The Sirena app, its design, rendering styles, name and logo are our property or licensed to us. We grant you a personal, revocable, non-exclusive, non-transferable license to use the app on Apple devices you own or control, as permitted by the App Store terms. No other rights are granted.

13. Disclaimer of warranties

THE SERVICE IS PROVIDED "AS IS" AND "AS AVAILABLE", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, ACCURACY, RELIABILITY OR NON-INFRINGEMENT. WE DO NOT WARRANT THAT CHARTS, POSITIONS, INSTRUMENTS OR ANY OTHER DATA ARE ACCURATE, COMPLETE OR CURRENT, THAT THE SERVICE WILL BE UNINTERRUPTED, TIMELY, SECURE OR ERROR-FREE, OR THAT DEFECTS WILL BE CORRECTED. NOTHING IN THE SERVICE CONSTITUTES NAVIGATIONAL, METEOROLOGICAL, LEGAL OR OTHER PROFESSIONAL ADVICE.

14. Limitation of liability

Your statutory rights. Nothing in these terms excludes, restricts or modifies any right, remedy, guarantee or warranty that the law of the country where you live gives you and that cannot lawfully be excluded or limited. This includes the consumer guarantees under the Australian Consumer Law, the UK Consumer Rights Act 2015, the consumer laws of the EU and EEA member states, and the consumer laws of your US state or Canadian province. Where the law allows our liability for a failure to meet such a guarantee to be limited, it is limited to supplying the service again or paying the cost of having it supplied again. The limits in this section apply only to the extent the law of your country allows.

Nothing in these terms limits liability for death or personal injury caused by our negligence, for intent or gross negligence, or any other liability that cannot be limited by law. Subject to that, and to the maximum extent permitted by law: (a) we are not liable for indirect, incidental, special or consequential loss, loss of profit, data or use, or for vessel damage, grounding, collision or salvage costs resulting from reliance on the app contrary to Section 3; (b) our total liability for all other claims in any 12-month period is limited to the greater of EUR 50 or the amount you paid for the app in that period. Your statutory rights above are not affected.

15. Indemnity

You will indemnify us against claims, damages and costs (including reasonable legal fees) caused by your breach of law or your wilful misuse of the service or of other users' data. If you are a consumer, this applies only to the extent the law allows.

16. Apple

These terms are between you and us, not Apple, and Apple is not a party to them. Apple has no obligation to provide support or maintenance for the app. If the app fails to conform to any applicable warranty, you may notify Apple and Apple will refund the purchase price, if any; to the maximum extent permitted by law Apple has no other warranty obligation. We, not Apple, are responsible for addressing any claims relating to the app, including product liability claims, claims that the app fails to conform to any legal or regulatory requirement, consumer protection or similar claims, and any third-party claim that the app infringes intellectual property rights. You confirm you are not located in a country subject to a US Government embargo or designated as a terrorist-supporting country, and are not on any US Government list of prohibited or restricted parties. You must comply with applicable third-party terms, such as your wireless carrier's terms, when using the app. Apple and its subsidiaries are third-party beneficiaries of these terms and may enforce them against you.

17. Termination

You can stop using Sirena and delete your account in the app at any time. We may suspend or terminate the service or your access for breach, legal requirement, security risk, or discontinuation of the product; where feasible we will give reasonable notice. Sections 3 and 9 to 17 survive termination.

17a. Worldwide by design

The Sirena family of apps (Sirena Seafarer, Sirena.Club and Sirena Logbook) is built for seafarers and boat owners everywhere. Whether a particular app, feature, subscription or price is offered in your country is decided per App Store country. It depends on Apple's rules and on the laws and regulations that apply there, including obligations for online platforms, which can change over time. Where an app or a feature is not offered in your country, the benefits that depend on it, such as Logbook Pro included with a Sirena.Club membership, cannot be used there. Every app in the family stays fully usable on its own and sells its own subscription through the App Store. Purchases and refunds are handled by Apple under its terms. Nothing in this section limits your rights under the consumer law of your country.

18. Changes, force majeure, severability

We may update these terms. We will give at least 30 days' notice of material changes in the app. If you do not agree, you may stop using the app and cancel any subscription before the change takes effect. We are not liable for delay or failure caused by events beyond our reasonable control (including network, cloud-provider or GNSS outages, weather, war, or acts of authorities). If a provision is held unenforceable, the rest remains in force; the invalid provision is replaced by a valid one closest to its intent. Our failure to enforce a provision is not a waiver.

19. Governing law

These terms are governed by the law of the Republic of Bulgaria. Disputes go to the competent Bulgarian courts. If you are a consumer in the EU/EEA, you also keep the protection of the mandatory rules and the courts of your country of residence. Consumers may also refer disputes to the conciliation committees of the Bulgarian Commission for Consumer Protection (kzp.bg).

Who we are

Sirena Seafarer is provided by Anton Dimitrov, self-employed, Varna, Bulgaria, VAT BG181579150. Questions, complaints or claims: [email protected]

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