Anchor Alarm Pro
GPS drag watch for sailors
Free · Designed for iPad. Not verified for macOS.
Sleep easy at anchor. Anchor Alarm Pro watches your GPS position and sounds a loud alarm the moment your boat drags - even through the silent switch and overnight.
Anchor Alarm Pro turns your iPhone into a dependable anchor watch. Drop your anchor, set a safe radius, and the app sounds a loud, escalating alarm the instant your boat drags outside the zone, so you can actually sleep at anchor.
KEEPS YOU SAFE OVERNIGHT
• Loud alarm that overrides the silent switch and rings even when the phone is asleep
• Soft pre-alert first, then a full alarm if you don't respond
• Smart drag detection that ignores normal swinging and won't false-alarm when you motor up to retrieve the anchor
FLEXIBLE ANCHOR ZONES
• Simple circular safe zone around the anchor
• Sector zones for swing on a single tide line
• Bow/stern corridor for Mediterranean and stern-to mooring: point your bow and set how far the boat may move
ACCURATE POSITION, YOUR WAY
• Built-in iPhone GPS
• External Bluetooth GPS receiver for better accuracy
• NMEA 0183 over TCP/UDP from your chartplotter, or Signal K from your boat network
• Auto-selects the most accurate connected source
WATCH FROM YOUR PHONE OR FROM SHORE
• Share a short code to link a second device, no account, no login
• One phone stays on the boat; another monitors remotely and gets the same drag alarm via push notification, even backgrounded
• Live boat position, track history, and battery status of the boat's device
BUILT FOR REAL CRUISING
• Live map with your track, swing circle, and OpenSeaMap-style detail
• Battery-conscious: eases off GPS while holding, sharpens up near the edge or while dragging
• Scrub back through your night's track to see exactly where you sat
Anchor Alarm Pro is made by sailors, for sailors. Set it once and trust it.
Ratings & Reviews
The map now keeps the boat centred, so it stays in view while dragging. A stern-to berth with lines ashore is drawn at the right zoom instead of a dot in the bay. The app runs on iOS 17 now, so older iPhones can keep watch too.
The developer, Plapp, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Location
- Contact Info
- User Content
- Identifiers
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Bastad Makerspace
- Size
- 7.6 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.
- iPhone
- Location
- This app may use your location even when it isn’t open, which can decrease device battery life.
- Languages
English and 13 more
- English, Croatian, Danish, Dutch, Finnish, French, German, Greek, Italian, Norwegian Bokmål, Polish, Spanish, Swedish, Turkish
- Age Rating
4+
- 4+
- Copyright
- © 2026 Dupo