Best Anchor Alarm Apps for iPhone (2026 Comparison)
Choosing the right anchor alarm app can mean the difference between a peaceful night at anchor and a dangerous situation. We compared the top anchor watch apps available in 2026 to help you find the best fit for your sailing needs.
What to Look for in an Anchor Alarm App
Before diving into individual apps, here are the essential features every good anchor alarm should have:
- Reliable background GPS — the app must continue tracking when the screen is off and the phone is locked
- Loud, persistent alarm — it needs to wake you from sleep, not just show a notification
- Adjustable safe radius — different anchorages need different alarm distances
- Low battery consumption — it needs to run all night without killing your phone
- Simple, quick setup — when you're tired after a day of sailing, you don't want to fight with complicated settings
The Best Anchor Alarm Apps Compared
Safety Anchor Alarm
Pros
- Completely free — no subscriptions
- Background GPS monitoring
- Lock screen widget
- Night mode
- Anchor points library
- Anchoring calculators
- Configurable update intervals
Cons
- iOS only (no Android yet)
- New app — smaller user base
Verdict: Best free option with a complete feature set. Ideal for sailors who want reliable monitoring without paying for subscriptions.
Ankeralarm
Pros
- Large anchorage database (685K+)
- Cross-platform
- Community features
- Remote monitoring (Pro)
Cons
- Pro features require subscription
- Can be complex for new users
Verdict: Strong choice for cruisers who value community features and a large anchorage database.
Anchor Alert (PredictWind)
Pros
- Weather integration
- N2K instrument data
- AIS target display
- Backed by PredictWind
Cons
- Full features require DataHub hardware ($299+)
- Overkill for basic anchor monitoring
Verdict: Best for sailors already in the PredictWind ecosystem with NMEA 2000 instruments.
Anchor Pro
Pros
- Apple Watch support
- Telegram alerts to crew
- Simple interface
Cons
- Paid upfront
- iOS only
- No free tier
Verdict: Good option if Apple Watch support is a must-have. The Telegram alert feature is useful for crew coordination.
Phone App vs. Chartplotter Anchor Alarm
Many chartplotters (Garmin, Raymarine, B&G) have built-in anchor alarm features. How do they compare to phone apps?
- Phone apps are louder — your phone is typically in the cabin with you, while the chartplotter is at the helm. A phone alarm is more likely to wake you.
- Phone apps are more portable — you can take the alarm ashore if you dinghy to a restaurant.
- Chartplotters have better GPS — external GPS antennas on chartplotters are generally more accurate than phone GPS.
- Phone apps don't drain boat batteries — no need to leave the chartplotter and instruments running all night.
The best approach is to use both: set the chartplotter alarm as a backup and rely on a phone app as your primary alert.
Tips for Using Any Anchor Alarm App
- Keep your phone plugged in. GPS tracking drains battery. Plug in to a USB charger for overnight use.
- Set the right radius. Too tight and you'll get false alarms from normal boat swinging. Too wide and you won't be alerted early enough. Start with 40-50 meters for a typical anchorage.
- Wait for the anchor to set. Don't activate the alarm immediately after dropping anchor. Let the boat settle on the hook first, then set your alarm position.
- Test the alarm sound. Make sure the volume is up and the alarm is loud enough to wake you. Some phones have Do Not Disturb modes that can silence alarms.
- Use it alongside good seamanship. An app is a tool, not a substitute for proper anchoring technique, adequate scope, and awareness of conditions.
Our Recommendation
For most sailors, Safety Anchor Alarm offers the best combination of features and value. It's completely free with no hidden costs, has all the essential features (background GPS, loud alarms, adjustable radius), plus extras like a lock screen widget, night mode, and anchor points library.
If you need cross-platform support (Android), Ankeralarm is a solid choice. If you're already invested in the PredictWind ecosystem with NMEA 2000 instruments, Anchor Alert integrates beautifully with that setup.
Regardless of which app you choose, the most important thing is to actually use one. Too many sailors skip the anchor alarm and rely on hoping for the best. A simple app on your phone could save your boat, your safety, and your peace of mind.
Frequently Asked Questions
What is the best free anchor alarm app for iPhone?
Do anchor alarm apps work with the screen locked?
Are anchor alarm apps reliable enough for overnight use?
Do I need internet for an anchor alarm app to work?
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