Celestial navigation, offline charts, weather routing, and an AI assistant — one connected platform for everyone who takes the open ocean seriously, from licensed officers to bluewater cruisers and offshore crews. Online when you have signal, fully functional when you don't.
Each module talks to the others. A sight reduction flows straight to your plotting sheet and logbook — no re-entry, no separate apps.
Full sight-reduction pipeline, star finder, running fixes, and an interactive plotting sheet. Works with no GPS and no internet.
When GPS is jammed, spoofed, or simply dead, celestial navigation is the only fully independent way to fix your position. CHIEFMATE runs the entire workflow on-device — no tables, no almanac, no separate calculator.
NOAA raster and ENC vector charts stored on-device. Plan routes, drop waypoints, export GPX — fully functional offline.
Download the charts you need before you leave the dock. They live on your device and work with zero signal, anywhere on earth. Especially powerful for delivery captains: plan an entire delivery passage in advance, drop every waypoint, export the route, and hand over a clean voyage record at the end.
Live AIS targets on your chart with CPA/TCPA alarms, set & drift, under-keel clearance, and a motion predictor — pilot-grade awareness.
A situational-awareness layer that overlays real-time AIS traffic on the chart and fuses it with live current and under-keel clearance — the kind of picture a harbor pilot carries, on the independent backup box. Runs from an internet AIS feed, or a USB AIS receiver for the full underway picture offline.
ECMWF-model weather with animated wind, swell, and current overlays. GO / CAUTION / NO-GO routing assessment per leg.
When you have a connection, pull the same ECMWF model the professionals use — the European model that consistently tops global forecast-skill rankings — and see your whole weather picture before committing to a passage.
A 3D loading computer with real-time GM, trim, list, and IMO intact-stability criteria as you adjust tanks and cargo.
A full loading computer that shows your vessel floating in 3D and recalculates stability the instant you move weight. Built for commercial operators and anyone carrying serious load.
Ask questions in plain English and get answers drawn from your onboard reference library — no connectivity required.
Ask a question in plain English and get an answer grounded in the reference library stored on your device. Your questions never leave the boat.
A topic-by-topic learning library — from the Rules of the Road to celestial navigation — plus full USCG exam prep.
Whether you're upgrading your license or just want to be the most capable person on the boat, the learning library explains every topic in plain language with the formulas and tips that matter.
Plus digital logbooks, tides & currents, ocean & coastal track planning, towing calculations, engineering tools, crew-rotation scheduling, radio & GMDSS reference, emergency procedures, expiry & certificate tracking, USCG inspection checklists, and full USCG license-exam prep — 20+ integrated modules in one platform, online or offline.
Modern navigation rides on satellites and a constant connection — fragile links that can be jammed, spoofed, knocked offline, or, in a worst case, physically lost.
A single chain-reaction of collisions in orbit can turn low-Earth orbit into a field of debris — and once it starts, it can feed on itself, degrading the satellites that GPS, communications, and weather all depend on. Analysts have modeled scenarios where the systems the modern world leans on unravel within a matter of days.
In any serious conflict, navigation and communication satellites are among the first targets — and GPS jamming and spoofing are already a daily reality in parts of the world. When the signal degrades, the electronic bridge most vessels rely on degrades right along with it.
An entire generation came up navigating by GPS — and that's no knock on anyone; the tools are simply that good. But if they vanished tomorrow, even seasoned mariners would be reaching back for celestial navigation, dead reckoning, and the sextant after years away from them.
CHIEFMATE keeps those capabilities alive and instant. It automates the time-tested methods — you take the sextant sight, it does the math and gives you your position — so when the signal ends, you're not reaching for a memory. You're reaching for CHIEFMATE.
The same platform scales from the recreational cockpit to the commercial bridge.
Officers and masters who need professional tools and certified-grade reference at the chart table.
Sailors making trans-ocean passages who want GPS-independent navigation and weather they can trust.
Serious offshore crews running far past the sight of land who need real navigation and a real backup.
The same connected toolkit — delivered in whichever form fits the way you operate. One account works across all four.
Log in from any computer or tablet and use the platform instantly — nothing to install. Ideal for planning ashore, at the dock, or anywhere you have a connection.
Download the app and your own machine becomes the server — the full offline experience, with charts, AI, and navigation all running locally and no internet required, anywhere on earth.
Download for Mac & Windows →The full CHIEFMATE experience in your pocket. Ideal for recreational mariners, weekend captains, and anyone who wants tide tables, weather, and navigation tools on the water without a laptop.
A rugged, battery-powered, self-contained navigation computer with everything pre-loaded. Solar-capable and built for the bridge or the ditch bag — the ultimate independent backup when the ship goes dark.
The full platform pre-loaded on a rugged, battery-powered, solar-capable device — a self-contained bridge you can carry aboard any vessel in minutes.
Inside a weatherproof case sits a complete maritime computer that runs entirely on its own power, charges from the sun, and works with no internet, no GPS signal, no cell service, and no subscription. When the ship's systems go dark, CHIEFMATE doesn't.
GPS jammed offshore at night. The chartplotter subscription lapsed. A lightning strike took the electronics. Whatever the cause, CHIEFMATE is the independent backup in the ditch bag: fix your position by sextant, find the safe channel on stored charts, look up an emergency medical procedure, and keep a legal logbook — all on battery, all offline. It is, at its core, a lifeboat for your digital navigation.
We'd rather earn your trust than oversell. Here is exactly where this platform stands.
What it is: the most complete offline-capable bridge toolkit a mariner can carry — built on official NOAA charts, the full CFRs, Bowditch, and real naval-architecture math, by a working licensed officer who uses it at sea.
On the desktop app and the hardware unit, nearly everything runs entirely on-device. Here's the honest breakdown:
Works completely offline: celestial & terrestrial navigation, ocean track plotting, charts and voyage planning (once downloaded), the stability computer, logbook, ship specifications, the full reference library and study material, signals reference, emergency procedures, and — on the hardware unit — the AI assistant.
Needs a connection: live weather & routing, downloading or updating charts, NOAA tide & current station predictions (an offline tide calculator is built in), the AI assistant on the desktop and web apps (it relays through our server; only the hardware unit runs the AI fully on-device), account sign-in and billing — and the web app itself, since it runs in your browser. Every feature that needs a connection tells you clearly when it's unavailable.
Anytime. Upgrade for a voyage that needs charts and stability, downgrade when you don't. Billing is prorated.
No. CHIEFMATE is a professional planning, reference, and backup tool. It complements your vessel's certified equipment — it doesn't replace it.
The software runs in your browser on any device. The hardware unit is a self-contained, rugged appliance with everything pre-loaded — ideal as an independent backup that never depends on ship's power or connectivity.
Commercial mariners handle sensitive information — vessel specifications, cargo details, voyage plans, crew data. We built CHIEFMATE's security to match the seriousness of that responsibility.