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
5.0
out of 5
1 Ratings
Drop the anchor with one touch: hold Set Up Watch, or the new Drop Anchor Here button on the map, and the watch starts where the boat is. To move the anchor, hold it on the map and drag it: the safe zone moves with it, and you confirm the new spot when you let go. The track is drawn in much finer detail, so you can tighten the radius to the boat's real swing. On iOS 26, holding the anchor and dragging the corners of a no-go area work again. The "While Using" location warning is gone too: the watch keeps its GPS in the background either way.
Version 1.12.0
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
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
Seller
Bastad Makerspace
Size
8.4 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.
Location
This app may use your location even when it isn’t open, which can decrease device battery life.