Seamrun

Find the seam.

Today's sea temperature with the breaks drawn for you. It opens 60 miles out with no signal.

Join the waitlist See how it works ›

Launching Monday 7 June 2027 · iPhone, iPad and Android

Seamrun on three iPhones: the readout sheet, the sea temperature map with a break labelled 2.1 °F, and Night mode in red. Seamrun on three iPhones: the readout sheet, the sea temperature map with a break labelled 2.1 °F, and Night mode in red.

Why Seamrun

Every pass. Every break.
Every US region.

Hourly
GOES every hour, plus every polar satellite pass, each with its age.
60 nm
Packs open offshore with no signal and no sign-in.
40 MB
Three days of your region, every layer, about the size of a few photos.
$79.99
A year for every US region. Seven days free to try.

Breaks

Breaks, drawn for you.

Each break is measured in °F per nautical mile on real satellite passes, then labelled with how far it is from your inlet. No guessing from a smoothed model.

Map of the Texas coast with sea temperature in colour, break lines labelled 2.1 °F, a saved spot, NOAA buoy 42020 at 79.1 °F and the readout at the crosshair. Map of the Texas coast with sea temperature in colour, break lines labelled 2.1 °F, a saved spot, NOAA buoy 42020 at 79.1 °F and the readout at the crosshair.
App preview with sample data.

Three strengths

Thicker lines are stronger breaks. Pick 1, 2 or 3 °F and up.

From your inlet

“24 nm SE of Port Aransas” means something at the dock.

Checked against buoys

NOAA buoys show their last reading right on the map.

Features

Built for the run.

Offline

Opens with no signal.

Download at the dock. Sixty miles out in airplane mode, the map, readout, spots and catch log all work, with no sign-in.

Two offline pack cards: Texas / NW Gulf ready, Central Gulf downloading. Two offline pack cards: Texas / NW Gulf ready, Central Gulf downloading.

Night mode

Red at 4 a.m.

Keeps your night vision. One tap, or on automatically at sunset.

The readout, status pill and a break label in Night mode red.

Every pass

Every pass, with its age.

Satellite, time and how old it is, on the map. Never a fake date.

Badges: Observed 2 h ago · GOES-19, Observed 6 h ago · NOAA-21, Older than usual · 30 h, Backup source · MUR blend. Badges: Observed 2 h ago · GOES-19, Observed 6 h ago · NOAA-21, Older than usual · 30 h, Backup source · MUR blend.

GPX

Your spots on any plotter.

Garmin, Simrad, Lowrance, Raymarine, Furuno, Humminbird. Break lines go too.

Two saved spots ready to export as GPX. Two saved spots ready to export as GPX.

Catch log

The water at every bite.

Log a catch in three taps. Water, chlorophyll, depth and the nearest break fill in, even offline.

Catch details: water temperature, chlorophyll and depth. Catch details: water temperature, chlorophyll and depth.

Honest data

Checked against NOAA buoys every night.

Satellites read the skin of the water. We compare our map with buoys nightly, publish the result, and show the nearest buoy right on the map.

13 of 16buoys within 1 °F on the first test run (Oct 2026)

Offline

Download at the dock.
Open it offshore.

Sixty miles out with no signal, Seamrun opens without signing in. The map, the readout, your spots and your catch log all keep working, and every image shows exactly how old it is.

  1. Pick your region and daysAbout 31 MB for three days on Wi-Fi.
  2. Lock the phone and goIt finishes in the background. A push says when it's ready.
  3. Open it offshoreNo signal, no login. The pack shows its real age.
iPhone showing the map offline with a pack downloaded at 9 p.m. iPhone showing the map offline with a pack downloaded at 9 p.m.

iPad and foldables

Bigger screen. Bigger water.

On iPad, iPhone Duo and Android foldables the map runs edge to edge with a side panel for the readout, and the menu floats on the side, clear of the buttons.

iPad with the map edge to edge and the readout in a side panel. iPad with the map edge to edge and the readout in a side panel.
iPad · side panel
Unfolded iPhone Duo with the map and a side rail. Unfolded iPhone Duo with the map and a side rail.
iPhone Duo unfolded · side rail

Tested in airplane mode

3 of 4

popular offshore apps showed no usable sea temperature when we opened them in airplane mode (our test, October 2026). Seamrun packs open without signal or an account, and every image shows how old it is.

Pricing

Less than a tank of fuel a year.

Every US region in every plan. Seven days free. Cancel anytime.

Recommended

Seamrun

$79.99 a year

or $11.99 a month · 7 days free

  • Every US region
  • Every satellite pass, breaks drawn
  • Chlorophyll, currents, eddies, sargassum, salinity
  • Offline packs that open with no signal
  • GPX to any plotter
  • Catch log with the water at every bite
Join the waitlist

Seamrun Pro

$129.99 a year

7 days free

  • Everything in Seamrun
  • Subsurface temperature, 10 to 100 m
  • Alerts when your spot hits your numbers
  • Encrypted sync across devices
  • 72-hour playback
  • Tournament pages
Join the waitlist

Free version: yesterday's map for one region. Trials start in the App Store or Google Play at launch.

Questions

When does it launch?

Monday 7 June 2027 on iPhone, iPad and Android, for every US region.

How accurate is satellite temperature?

Satellites read the top skin of the water, so your boat sensor can differ by a degree or two, especially on calm afternoons. We check our maps against NOAA buoys every night and publish the results.

Do I need an account?

No. Open the app and use it. Sign in only if you want to sync across devices.

Where do my spots go?

They stay on your phone. If you turn on sync, they are encrypted before they leave it.

Is it for navigation?

No. Seamrun is for planning. Carry official charts, watch the NWS marine forecast and use your own judgment.

Find the seam
before you leave the dock.

One email on launch day. Nothing else.

Launching Monday 7 June 2027 · iPhone, iPad and Android · How we use your email