Marinate
One-tap MOB
Marks the person's position the instant you tap, then navigates you straight back — bearing, distance and ETA to the mark.
Works fully offline
Safety at sea
Built for the moment everything changes.
Most of the time, Marinate is your chartplotter. But the sea does not schedule its bad moments. A crew member goes over. The anchor lets go at 3 a.m. A ship closes in through the haze. For those moments, Marinate keeps its alarms armed and one promise: MOB and the anchor alarm are free, forever.
No account. No tracking. Everything stays on your phone.
The safety suite
Five layers between you and a bad day
Each one watches a different risk, from a crew member in the water to a ship converging in the fog. The two you may need with no signal lead the list.
Anchor alarm
Set a watch circle over your anchor. If the boat drags outside it, the alarm sounds before the shoreline arrives. Keep the app open — the watch runs on screen.
Works fully offline
Collision alarm
Live AIS traffic with CPA/TCPA worked out for every vessel around you, and an alarm when a track gets too close.
Premium · free AIS key + signal
Shallow-water alarm
Reads live depth from your boat's instruments over SignalK/NMEA and warns the moment the bottom comes up to meet you.
Premium · via SignalK/NMEA
Night mode
A dimmed, red-shifted palette that keeps the chart readable without burning away the night vision you need at the helm.
On every plan · one switch
Man overboard
One tap. Straight back.
When someone goes in the water, seconds decide everything, and nobody remembers menus. The MOB button is one tap: Marinate drops a mark at the exact position and immediately starts auto-return navigation to it.
From that instant the screen is about one thing only: getting back. Bearing to the mark, distance off, and your position updating live as you turn the boat around.
- Instant mark — position captured the moment you tap, no confirmation dialogs.
- Auto-return navigation — the app switches itself into a Go-To back to the mark.
- Works offline — GPS and your downloaded charts are all it needs.
Anchor watch
Set the circle. Watch it hold.
Drop the hook and set the watch circle around your anchor position. Marinate checks your GPS position against that circle on every fix, and if the anchor drags and the boat swings outside it, the drag alarm sounds while there is still time and sea room to do something about it.
Leave Marinate open with the screen on. The watch runs in the app, so locking the phone or switching away stops it — the app keeps the screen awake for you, and tells you plainly if it ever finds a gap in its own watch. Background monitoring with the phone locked is coming; we would rather say that than let you think it already works.
Every stay is written into your anchorage log, so the bays where you slept soundly — and the ones where you didn't — are on record for next season.
- Watch circle — you choose the radius that matches your scope and swing.
- Drag alarm — sounds the moment your position leaves the circle.
- Honest about gaps — if the app was backgrounded, it says how long the watch was not running.
- Anchorage log — a record of where you anchored and how it held.
Collision avoidance
Know who's converging — before it's obvious
Switch on Premium's AIS layer, paste in a free aisstream.io key, and Marinate overlays live vessel traffic on your chart — continuously working out, for every vessel, the two numbers that decide whether you should care.
CPA
0.4 nm
TCPA
6 min
- CPA — Closest Point of Approach. If you both hold course and speed, the closest that vessel will ever get to you.
- TCPA — Time to CPA. How many minutes until that closest moment happens.
- The alarm — sounds when both numbers drop below your thresholds: close and soon, while altering course is still a small, calm decision.
Part of Premium's AIS layer, running on your own free aisstream.io key. Live AIS needs signal, which is exactly why the MOB and anchor alarms don't.
Depth & darkness
Guarded from below. Ready for the dark.
Hook Marinate up to your boat's instruments over SignalK/NMEA, part of the Premium instrument link, and it reads your depth sounder live on the boat's own network, no internet needed. Set a minimum depth, and the shallow-water alarm sounds the moment the water under your keel thins past it — whether you're threading a channel or the tide is quietly falling under an anchored boat.
Night mode is on every plan: one switch dims the whole app into a red-shifted palette. Charts, instruments and alarms stay readable while your eyes stay adapted to the dark. That adaptation is the difference between seeing the unlit buoy and not.
- Live depth — from your own sounder via SignalK/NMEA, the Premium instrument link.
- Your threshold — set the minimum depth that fits your draft.
- Red-shifted palette — night mode built for the helm, free on every plan.
Our pledge
MOB and the anchor alarm are never paywalled
One-tap MOB with auto-return navigation, and the anchor watch circle with its drag alarm, are free for every sailor, on every plan, forever. Both run entirely offline. We will not put a subscription between you and those alarms.
The honest footnote: the collision and shallow-water alarms ship with Premium's AIS and SignalK layers, because they cannot exist without those live data links. The alarms come with the layer — never sold separately on top.
One-tap MOB
Anchor drag alarm
Fully offline
No account required
Know its limits. Marinate uses community chart data (OpenStreetMap, OpenSeaMap, EMODnet), not official ENC charts. It is an aid to situational awareness and must not be used as the sole means of navigation. Alarms depend on your phone's GPS, your instruments and your settings — always carry official charts and keep a proper lookout.
Put it aboard before your next sail
Marinate installs in seconds, and the safety suite is armed from the first launch. When you want them, Premium's AIS and SignalK layers add the collision and shallow-water alarms.