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iOS 18+iPadOS 18+macOS 15+Version 1.0

SeaTally

Your sea time, counted the way the rules count it.

A Yachtmaster application, or a USCG renewal, comes down to a count: days at sea, miles, night hours, qualifying passages — under rules that are easy to get wrong. A qualifying day is not a calendar day; the ten-year window is clipped, not filtered; sail time does not count towards a power exam. SeaTally records the passage as you sail it, measures the miles from the track itself, works the rules out for you, and shows what is still missing in plain words. It runs entirely on your device: no account, no cloud, nothing leaves the boat.

Coming soon to the App Store

Everything you need, nothing you don't

Eligibility, not just a total

Pick your certificate — RYA Coastal or Offshore, sail or power, or a USCG renewal — and every requirement shows its progress and what is still missing, in plain words.

Miles measured from the track

Start recording at departure, stop on arrival. Distance follows the great circle along the track, night hours come from the sun's real position, and a signal gap is counted in a straight line and marked as estimated.

Qualifying days worked out, not guessed

A qualifying day is eight consecutive hours living aboard with most of it at sea — at most one per 24 hours, and never from time in port alone. SeaTally works it out by crossing your time aboard with your passages.

The RYA record and CG-719S forms

Export a sea time record in the RYA/MCA layout — tidal and non-tidal totals copy straight into Section 3 — and CG-719S forms, one per vessel and role, monthly grid filled, ready to sign.

Nothing leaves the boat

No account, no cloud, no telemetry — and no Social Security Number: that box on the CG-719S prints empty, for you to fill in by hand. Recording works with no signal at all, which is the normal state at sea.

Never locked in

A re-importable CSV export, automatic JSON backups and a 30-day trash. Exports, eligibility and backups are never locked — with or without Pro.

The counting rules

The rules are trickier than the totals.

A weekend with two day sails is two qualifying days, not one. A 2,800-mile passage that straddles the ten-year cut-off still counts for the part inside the window. Time on a motor yacht adds nothing to a sail exam, and a vessel over 24 m has its miles halved. Getting one of these wrong costs months. SeaTally encodes each rule as data, with a named test behind it, and returns what it excluded — and why — alongside every total.

  • A qualifying day: 8 consecutive hours aboard, most of it at sea, one per 24 h
  • The ten-year window clips a passage, it does not discard it
  • Discipline must match: sail time does not count towards a power exam
At sea

No signal is the normal state.

Offshore there is no network, and a passage lasts longer than a lit screen. SeaTally keeps recording with the phone locked and in your pocket, writes the session to disk at every fix — so a flat battery or a crash never costs you the night — and if the GPS drops out, those miles are counted in a straight line and clearly marked as estimated rather than passed off as measured.

  • Recording survives the screen going off, and the app being killed
  • Signal gaps are shown on the map and counted as estimated
  • Impossible positions are discarded — they would add miles you never sailed

Screenshots

The real interface — click any screen to zoom in.

How close you are

Every requirement of your certificate, its progress, and what is still missing.

The passage on its track

Distance, night hours and the signal gaps — measured, and shown on the map.

Simple, fair pricing

Start free. Upgrade once. Own it forever.

Free

$0

The whole logbook, capped at 25 passages.

  • 25 logged passages, fully featured
  • GPS recording, miles and night hours
  • Eligibility for every credential
  • RYA record, CG-719S and CSV exports
  • Automatic backups and 30-day trash
  • iPhone, iPad and Mac
Coming soon to the App Store

SeaTally Pro

SeaTally Pro

$30one-time

Unlimited passages. One purchase, no subscription, unlocked on every device.

  • Everything in Free
  • Unlimited logged passages
  • Universal purchase — iPhone, iPad and Mac
  • Restore on any new device
Coming soon to the App Store

Payments are processed securely by Apple through the App Store.

System requirements

Operating system
iOS 18+, iPadOS 18+, or macOS 15 Sequoia+
Location
Used on-device to measure distance and night hours while recording; never transmitted
Internet
Never required — the app has no account and no server
Purchase
Free download; Pro is a one-time in-app purchase (universal across iPhone, iPad, Mac)

Overview

Category
Productivity
Version
1.0
Released
August 27, 2026
Updated
August 27, 2026

Frequently asked questions

Changelog

v1.0

Initial release

  • GPS passage recording that survives a locked screen, a flat battery and a crash
  • Miles along the track, night hours from solar position, signal gaps marked as estimated
  • Eligibility for RYA Coastal and Offshore (sail and power) and USCG renewal
  • Qualifying days from time aboard crossed with passages; qualifying passages detected
  • RYA/MCA sea time record and CG-719S forms, one per vessel and role
  • Passage detail with its track on a map, re-importable CSV export, JSON backups, 30-day trash
  • English and French

Get SeaTally

Free to download and use. Unlock Pro anytime with a one-time purchase through the App Store.

Coming soon to the App Store