Rhumb Line Apps

Privacy Policy

Last updated: September 10, 2026

The short version: Our apps have no accounts, no ads, and no third-party analytics or tracking, and we never sell or share your information. Your trips, your boat and your settings stay on your device. There is exactly one thing that leaves it, and only because you press a button to send it: a mark you report to other boaters. Section 4 says what that contains and what happens to it.

This Privacy Policy explains how Rhumb Line Apps LLC (“Rhumb Line Apps,” “we,” “us,” or “our”) handles information in connection with our websites and mobile applications, including ICW Planner (collectively, the “Services”). By using the Services, you agree to this Policy.

1. What we never do

We designed our apps to work without knowing who you are. We do not:

2. Information that stays on your device

To do its job, the app stores and processes information locally on your device. None of this is sent to us:

3. Location information

ICW Planner offers optional features that use your device’s location: a spoken warning as you enter shallow water or a speed, no-wake, or manatee zone, the narration of places as you come level with them, and keeping your next-bridge time accurate while you are moving. iOS asks your permission before any of this happens, and the app works fully with location denied. Nothing you have paid for is locked behind granting it.

You can allow location in the background, and there is a reason to. A boater underway is usually steering by a chartplotter or another chart app, so ICW Planner is not the app on the screen at the moment a shallow-water or no-wake warning matters. A warning that arrives after you have gone past is worthless. If you grant background access, those spoken warnings and the narration keep working while the app is behind another one; if you grant only “while using the app,” they stop the moment ICW Planner leaves the screen. Either choice is fine, and you can change it whenever you like.

Wherever you set it, your position is worked out on your device and stays there. We do not transmit, store, or share your location, we keep no history of where you have been, and your position is never used for advertising or tracking. The one exception is a mark you deliberately send in, which carries the position you chose on the chart — see section 4. You can grant or revoke location access at any time in iOS Settings → Privacy & Security → Location Services.

4. Marks you choose to send us

ICW Planner lets you drop a mark on the chart — a shoal, a hazard, an anchorage, a marina, a dock, a mooring field, or a note — and, if you want to, send it in so it can warn or help the next boater. This is the only thing the app ever sends us about you, it never happens on its own, and you can use every other part of the app without ever pressing Send.

What a submitted mark contains. The position on the chart that you chose, the nearest mile marker, what kind of mark it is, the note you typed, an optional name or boat name if you filled that field in, and an identifier the app generated for the mark so that a retry does not create a duplicate. Nothing else. There is no account behind it, so there is nothing for us to attach it to.

What happens to it. Every submitted mark arrives in a review queue and is held there, invisible to everyone, until a person at Rhumb Line Apps looks at it. Nothing you send appears to another boater unless a reviewer approves it. If it is approved, the mark — including your note, and the name or boat name if you supplied one — may be published in the app to other boaters. Please do not put anything in the note or the name field that you would not want other people to read. What you may and may not send, and how to report something you object to, are set out in section 4 of our Terms of Use.

Your network address. The service that receives marks needs to be able to tell that many submissions came from the same sender, so that one person cannot bury the queue. It does that without keeping your address: the address is turned into a scrambled, salted value that cannot be turned back, and only that value is stored. We do not keep a log of raw addresses, because that would amount to a record of where boaters are, which is exactly what we set out not to have.

Taking one back. Write to privacy@rhumblineapps.com and we will remove a mark you sent. Because there are no accounts, please describe it — roughly where and when, and the note you wrote — so we can find the right one.

5. Purchases

Optional Pro features are sold as in-app purchases and subscriptions processed by Apple through the App Store. Apple handles your payment and receives the associated transaction information under Apple’s Privacy Policy. We do not receive or store your payment card details. We receive only the anonymous entitlement information needed to unlock the features you purchased.

6. Data sources the app contacts

To provide up-to-date marine information, the app retrieves publicly available data directly from government sources, and corrections to its own bundled data from our data host. These requests ask for public data (such as tide predictions for a station, or notices for a region) and do not include your personal information. When you use these features, your device connects to:

These providers may receive standard technical information inherent to any internet request (such as your IP address) and handle it under their own privacy practices. We do not control these third-party services.

7. How long we keep things

Your trips, settings, saved marks, and cached data live on your device and remain until you delete them or remove the app. Deleting the app removes all of it.

A mark you sent in is different, because its whole purpose is to be useful later: a shoal reported one season is still worth knowing about the next. We therefore keep submitted marks for as long as they are useful to other boaters, which may be indefinitely. You can ask us to remove one at any time, as described in section 4.

8. Children’s privacy

Our Services are intended for a general audience and are not directed to children under 13. We do not knowingly collect personal information from children.

9. Security

Data on your device is protected by iOS’s built-in security. Network requests use encrypted connections. Submitted marks are held in a private database that is not readable from the public internet: the service that receives them can only write, and reviewing them happens through a separate, access-controlled tool. We hold no accounts, no passwords, and no payment details, so there is nothing of that kind to be lost.

10. Your rights

Depending on where you live (for example, under the GDPR or CCPA/CPRA), you may have rights regarding personal information. In most cases we hold nothing about you at all, so there is nothing to access, correct, or delete. If you have sent us a mark and want to know what we hold or want it removed, write to privacy@rhumblineapps.com. Because there are no accounts, we can only find it from the details you give us.

11. Changes to this Policy

We may update this Policy from time to time. When we do, we’ll revise the “Last updated” date above. Material changes will be reflected on this page.

12. Contact us

Questions about this Policy or your privacy? Reach us at:

Rhumb Line Apps LLC
Email: privacy@rhumblineapps.com
Support: rhumblineapps.com/support