Comparison

Anchor Pro vs Buoyancy Calc

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Anchor Pro

This app helps boaters set and monitor their anchor position in real-time. It allows for defining safe zones, tracking boat movement, and receiving alerts for critical changes. Remote notifications and Apple Watch integration enhance its utility for secure anchoring.

Highlights
  • Set anchor location in real-time or manually
  • Define custom safe swing zones
  • Monitor boat movement and track history
  • Receive real-time alerts for position, GPS, and battery
  • Remote notifications via Telegram or email
  • Apple Watch companion app for key metrics
Features
Read full description

SET THE ANCHOR Set your anchor location in real time as you drop it, or specify it later by entering distance and bearing. Advanced users can also input exact coordinates. DEFINE THE SAFE ZONE Define the allowed swing area as a simple circle around the anchor, or create a more precise zone by setting two different radii at specific angles. MONITOR MOVEMENT Stay on top of every movement with comprehensive real-time data. Review key metrics on the main screen or switch to the map view to see your boat's track — ideal for analyzing whether your anchor is holding or dragging. GET ALERTED WHEN IT MATTERS Monitor position, GPS signal strength, and battery level — and receive alerts the moment any of these fall outside your set thresholds. REMOTE ALERTS Leave your phone on board and stay informed from shore. Receive alarm notifications via Telegram or email. With Telegram, you can also request a live status update at any time. APPLE WATCH Keep distance, bearing, and battery level on your wrist with the Apple Watch companion app — all updated in real time. TRY ANCHOR PRO FOR FREE Core features are always free. Want to explore everything? All premium features are available during a free trial period — no commitment required. Anchor Pro is ad-supported. Purchasing an Anchor Premium subscription removes ads and unlocks extra features. Payment is charged to your iTunes Account at confirmation. Subscriptions renew automatically at the same price unless auto-renewal is turned off at least 24 hours before the current period ends. You can manage auto-renewal anytime in your Account Settings. Anchor Premium is $6.99 USD/year (pricing may vary by country). Any unused portion of a free trial is forfeited upon purchasing a subscription, where applicable. Terms of use: https://links.ideaboys.net/anchor-ios-terms.html GOOD TO KNOW Anchor Pro uses background audio and location services to keep alerts active when the app is not in the foreground. Please note that continuous GPS use will drain your battery faster than usual.

About

Buoyancy Calc

Calculate the optimal weight for scuba diving based on environmental factors. Input your weight, water type, tank, and exposure suit to get a suggested weight for neutral buoyancy.

Highlights
  • Calculate suggested diving weight
  • Adjust for water type
  • Adjust for tank type
  • Adjust for exposure suit
  • Supports pounds and kilograms
Features
Read full description

Quickly find out the suggested weight you should add when scuba diving in different environments. Based on PADI's Peak Performance Buoyancy basic weighting guideline*. Enter your weight in pounds or kilograms, and additionally set the type of water, tank, and exposure suit to dial in a suggested amount of weight to help keep you neutrally buoyant. *Note that this app and the developer are not officially a representative of PADI. This app will give the user a good estimate of the weight needed for the environment selected, but there are always adjustments needed to achieve peak performance, based on gender, physique, exposure suit age, accessories, etc.

Screenshots

Anchor Pro4 screens
Buoyancy Calc1 screens

Verdict

The call

The clearest difference is rating: Anchor Pro at 4.8 against Buoyancy Calc's 3.1. Anchor Pro also leads on review sentiment (79% vs 40%) and ratings volume (3.6K vs 25). Buoyancy Calc's advantage is in-app purchases (none vs 1) and iOS requirement (15.6 vs 17.2). On price, update cadence, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Anchor Pro sells 1 in-app purchase, starting at $6.99 per year. Buoyancy Calc asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Anchor Pro holds the better App Store score, 4.8 against 3.1. That said, the two scores are not equally well evidenced: Anchor Pro has 3.6K ratings behind it against 25, so its average is the more settled of the two. Written reviews point the same way: 79% of Anchor Pro's written reviews are positive against 40% of Buoyancy Calc's.

UpkeepUpdate frequency

Anchor Pro ships an update every 2 months, Buoyancy Calc every 3 months. The most recent releases landed on October 23, 2026 and October 22, 2026 respectively.

Scorecard6 real differences · 4 level
Anchor Pro versus Buoyancy Calc: the parameters behind the verdict, then further details
ParameterAnchor ProBuoyancy Calc
PriceFreeFree
Rating4.8 (3.6K ratings) — better3.1 (25 ratings)
Positive reviews78.9% of reviews — better40.0% of reviews
Number of ratings3.6K — better25
Update frequencyEvery 2 months — betterEvery 3 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, Apple WatchiPhone, iPad, iPod
Requires iOS17.215.6 — better
Further details — not scored
Size23 MB1 MB
Age rating4+4+
DeveloperIdeaBoys GmbHEric Hamiter

Customer experience

Anchor Pro

All ratings3,496 ratings
Positive96.5%
Neutral1.7%
Negative1.7%
Written reviews180 reviews
Positive78.9%
Neutral3.3%
Negative17.8%

Buoyancy Calc

All ratings25 ratings
Positive44.0%
Neutral12.0%
Negative44.0%
Written reviews25 reviews
Positive40.0%
Neutral12.0%
Negative48.0%

Bugs and requests

Anchor Pro

Reported bugs

2 issues
  • App randomly shuts off
  • Anchor position tracking glitches

Requested features

3 requests
  • Customizable anchor icon/color
  • Integration with marine GPS/chartplotter
  • Ability to adjust alarm parameters remotely

Buoyancy Calc

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Anchor Pro

Subscriptions1
  • Anchor Premium7 Days trial$6.991 Year
None

Buoyancy Calc

No in-app purchases

Questions

Is Anchor Pro free?
Anchor Pro is free to download, with in-app purchases available.
Is Buoyancy Calc free?
Buoyancy Calc is free to download, with no in-app purchases.
Which has better reviews, Anchor Pro or Buoyancy Calc?
Anchor Pro is rated higher. Anchor Pro averages 4.8 out of 5 from 3.6K ratings, while Buoyancy Calc averages 3.1 from 25 ratings.
Do Anchor Pro or Buoyancy Calc have ads?
Neither Anchor Pro nor Buoyancy Calc shows ads.
Which is updated more often, Anchor Pro or Buoyancy Calc?
Anchor Pro ships an update every 2 months, and Buoyancy Calc every 3 months. Most recently, Anchor Pro was updated on October 23, 2026 and Buoyancy Calc on October 22, 2026.

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