Comparison

Cortex Onboard vs FastSeas

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

Head to head
About

Cortex Onboard

Configure and update your marine electronics, and monitor vital boat data remotely. Receive alerts, view AIS information, and manage anchor watch from your mobile device.

Highlights
  • Configure and update Cortex devices
  • View AIS information and alerts
  • Manage Anchor Watch remotely
  • Monitor boat sensors and NMEA 2000 instruments
  • View battery, pressure, and position data
Read full description

Cortex Onboard is free with your Cortex. Use it to configure your Cortex Hub and download updates to your Cortex devices with new features and improvements. You can also use Cortex Onboard to receive and manage alerts, view AIS information and instrument data anywhere on board your boat. View out-of-the-box sensors or NMEA 2000 networked instruments. - Setup is easy and free. - Use Cortex Onboard to configure and update your Cortex devices easily. - View AIS information and receive alerts on board direct to your device. - Manage Anchor Watch from the palm of your hand anywhere on board. - Use the Cortex Hub’s built-in sensors for battery level, barometric pressure and boat position. - Connect your Cortex Hub to NMEA 2000, or an external sensor, to add monitoring for wind, depth, bilge high water, temperature, shore power or security. - The Cortex Hub supports up to 10 WiFi devices (includes Handsets).

About

FastSeas

Features
Read full description

FastSeas is a weather routing and passage planning tool built for sailors. Give it a start and finish point, and FastSeas calculates the fastest and most comfortable route using live NOAA GFS and ECMWF weather forecasts, real ocean surface current data, your vessel's actual sailing performance, and your own comfort criteria — not just a straight line on a chart. WHAT FASTSEAS DOES • Weather Routing — enter a departure point, destination, and time, and get back a real calculated route: distance, passage time, and a full track overlaid on an interactive weather map. • Departure Planning — compare multiple candidate departure times side by side to find the best weather window for your passage. • Vessel Performance — teach FastSeas your boat's real polar performance (create one from a few basic inputs, import an existing polar file, or hand-edit the numbers yourself) so every calculation reflects how your specific boat actually sails. • Point Forecast — check detailed weather (wind, gusts, temperature, cloud cover, rain and pressure) and the sea (wave height, period and direction, with the wind sea and swells on GFS) at any point along your route or anywhere else on the chart. • Waves on the Map — see the sea as well as the wind: Significant Waves from GFS and ECMWF, and on GFS the Wind Sea, Swell 1 and Swell 2 that make it up. • Route Export — export a calculated route as GPX, KML, or KMZ for your chartplotter or other navigation software, or as a plain CSV/printable table. • Satellite Ready — FastSeas can also plan a route entirely by email, for sailors offshore with only a satellite communicator (Garmin inReach, Zoleo, and similar devices) and no regular internet connection. GETTING STARTED Sign in with a one-time code sent to your email — no password to remember or lose partway through a passage. An account is required to run routing calculations, and it keeps your vessel's performance and comfort settings between sessions. A FastSeas account includes a free tier for exploring the app. A Premium subscription removes the free tier's route-calculation limits. FastSeas is a planning aid, not a substitute for official forecasts, charts, or seamanship — mariners remain solely responsible for their own navigation decisions.

Screenshots

Cortex Onboard4 screens
FastSeas4 screens

Verdict

The call

The clearest difference is update cadence: FastSeas at every 9 days against Cortex Onboard's every 2 months. FastSeas also leads on iOS requirement (15.4 vs 18.5). On price, ads, in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Cortex Onboard ships an update every 2 months, FastSeas every 9 days. The most recent releases landed on November 3, 2026 and November 10, 2026 respectively.

Scorecard2 real differences · 8 level
Cortex Onboard versus FastSeas: the parameters behind the verdict, then further details
ParameterCortex OnboardFastSeas
PriceFreeFree
Rating3.8 (12 ratings) — better—
Positive reviews55.6% of reviews—
Number of ratings12 — better—
Update frequencyEvery 2 monthsEvery 9 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS18.515.4 — better
Further details — not scored
Size22 MB21 MB
Age rating4+4+
DeveloperGarmin New Zealand LtdExtempo LLC

In-app purchases

None

Cortex Onboard

No in-app purchases

None

FastSeas

No in-app purchases

Questions

Is Cortex Onboard free?
Cortex Onboard is free to download, with no in-app purchases.
Is FastSeas free?
FastSeas is free to download, with no in-app purchases.
Do Cortex Onboard or FastSeas have ads?
Neither Cortex Onboard nor FastSeas shows ads.
Which is updated more often, Cortex Onboard or FastSeas?
Cortex Onboard ships an update every 2 months, and FastSeas every 9 days. Most recently, Cortex Onboard was updated on November 3, 2026 and FastSeas on November 10, 2026.

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