Privacy Policy

CoastFinder does not know who you are. The app has no account, no analytics, no advertising and no tracking of any kind. The only time anything you enter leaves the phone is when you send us a suggestion or correction yourself, and it carries nothing that identifies you. This website counts its visits only as anonymous totals, with no cookies and no tracking scripts (below).

Checking for and downloading regions

Two regions are built into the app. When it is online, the app fetches the list of other regions from coastfinder.app when it starts and when you open Regions, and when you download one it requests that region's file from the same place. These are ordinary web requests for public files. The website's host sees the IP address that asked and which file was requested, as any web server does. No position, account or identifier is sent. Downloaded regions then work with no connection at all.

Showing the map

When it is online, the Map tab draws its coastlines, streets and place names from OpenFreeMap, a free public map service, by requesting the map tiles for the area on screen from tiles.openfreemap.org. The request does not contain your position, but the tiles are for the part of the map you are looking at, which is often where you are. OpenFreeMap receives the request and your IP address, and its handling of them is governed by OpenFreeMap's own terms. No key or account is involved. With no signal, the map draws the coastline built into the region packs instead and nothing is requested. This website's Viewpoint map uses the same service.

Checking for app updates

Small fixes to the app's own code can arrive between App Store releases through Expo's update service, which the app is built with. When it is online, the app asks that service whether a newer version exists. The request carries the app version, the platform, and a random installation number the update service creates the first time the app runs, which Expo uses to roll updates out in stages and to count how many phones have received one. It is not linked to your name, your Apple ID or your advertising identifier, and it carries no position. Deleting the app deletes it. Expo's handling of the request is governed by Expo's privacy policy.

Refreshing tide predictions

Depth estimates are corrected for the tide. Every region pack ships with about sixty days of tide predictions built in, so this works offline. When the app is online and those predictions are running out, it refreshes them from NOAA's public Tides and Currents service. That request contains a tide station identifier and a date range. It does not contain your position, but the station is one near you, so it does indicate the general stretch of coast you are on. NOAA receives the request and your IP address, and their handling of it is governed by their own privacy policy. No key or account is involved.

Suggestions and corrections

Three parts of the app let you help improve the catalog: Know this spot? Help improve it on a feature's detail card, for a wrong position, name, depth or height, or a feature that is not there; Tell us about it, in Search and under More, for something the app is missing; and I'm over it, offered when you are on a boat over a wreck. When you press Send, the app sends what you entered to coastfinder.app, which passes it to a review spreadsheet that only CoastFinder's owner can see.

A correction carries the feature, the region pack and app version, your note, your GPS position and its accuracy, your eye height, the bearing and distance the app computed, and, if you took a sighting, the heading and tilt of the phone. A suggestion carries what you typed and whatever position you chose to give: your GPS position, a pin on the map, typed coordinates, or none.

The suggestion form on this website's Help improve page sends the same: what you typed, and the position you chose, either coordinates you typed or, if you pick Where I am, the position and accuracy your browser shares after asking you. If sending fails, the form offers to put the same suggestion in an email from your own mail app instead, which carries your email address, used only to reply to you.

An I'm over it report carries the wreck, the region pack and app version, your GPS position averaged over the last few seconds with its accuracy, how many readings went into it, how widely they spread and when they were taken, how far and in which direction that is from the charted position, your eye height and your note. If you type a reading from your depth sounder, it also carries that depth, the time you entered it, and the tide NOAA predicted at that moment for the nearest station, so the tide can be taken off the depth.

None of them carries your name, your email address or any identifier, so a submission cannot be linked to you, or to any other submission. The website's host sees the IP address it came from, as any web server does; it is used only for a moment, to stop floods of submissions, and is not stored with them. Nothing is sent unless you press Send. With no signal, the submission waits on your phone and goes when you next have some. Submissions are used only to check and correct the chart data.

If you would rather, a correction can still go by email from your own mail app (Send by email instead). That carries your email address, which is used only to reply to you.