CH 16 · UK & Irish Sea

VHF Radio Assistant

Talk for me on the water

Mic fright? Stammer under pressure? Read the script calmly yourself — or tap once and let it call for you, word for word.

On channel

CH 80Marina call

Every call is scripted and ready before you press transmit — marina, harbour master, lock, Coastguard, VTS, vessels, or a buddy boat — with the right channel, your nearest marker or position, and both vessel names filled in for wherever you are. Say it yourself, calm and word-perfect, or let it speak for you, clearly, every time. No fumbling for words. No dead air. No guessing the channel.

Built at the helm for real UK and Irish Sea sailing, alongside live AIS tracking, offline charts, and collision alerts.

In development · not yet available

Home screen showing a vessel highlighted red with a close CPA warning — Sees the danger before you do

Flags a close-quarters vessel in red, with the COLREG call ready to go.

"FJORD BREEZE, FJORD BREEZE, this is sailing vessel SUNDANCER. I am half a mile north-east of buoy Q1, my heading is 195 degrees at 5.5 knots. I intend to pass port to port. Over."

Vessel name, nearest marker, heading and speed — filled in automatically, every time.

Engine failure? It already knows what to say

One tap on "Engine failure" and the call is written — position, course, speed and crew on board, all filled in automatically. Read it Standard, or switch to Paced for a steadier, word-by-word rhythm.

A pre-set priority list of who to call for this button — VTS, then a marina, then nearby vessels, and Coastguard as a last resort — Knows exactly who to call

A marina button calls the marina, a VTS button calls VTS — or set a button like Radio Check to offer several options, in priority order, like this one.

Update once. Stay in sync everywhere.

Duplicate a device's whole setup in one go — marinas, channels, custom buttons and all — or share a live intercept course, so whoever's on the second screen sees the same target, the same heading, the same ETA. Press send on one device, receive on the other, done.

A prompt before transmitting, telling you to turn the channel knob to 37 and set power to low before sending — Never guess the channel again

Tells you exactly which channel and power to set before you transmit.

Emergency button grid showing MAYDAY, Pan Pan, Sécurité, MOB, Relay and Cancel — One tap, and it's already written

MAYDAY, Pan Pan, Sécurité, MOB — every emergency call, pre-filled with your vessel name, position and lat/lng, ready before your hands even shake.

Safety and Assistance button grid showing Engine failure, Request tow, Fog warning, Medical, Medical detail and Salvage — For everything short of a Mayday

Engine failure, request a tow, call for medical help — the non-emergency calls that still need to go out clearly, one tap away.

What it does

Everything you need to make the call

CALL

Scenario call buttons

Marina, harbour master, lock, Coastguard, VTS, vessels, and buddy calls — each with the correct channel, nearest marker or position, and vessel names filled in automatically for wherever you are, plus its own script and reply suggestions.

Read it yourself, or let it speak

Every script is on screen, calm and ready to read — or tap once and text-to-speech reads it aloud clearly, ready to hold up to your radio's mic, key, and send, with a hard stop you can trigger at any time.

WARM

Voice Warmup

Open Voice Warmup in Settings to settle your breathing and pacing before you sail — then toggle the paced display on for real calls too, whenever you want that steadier rhythm.

DEMO

Practise for real, from your armchair

Demo Mode populates the app with realistic vessel traffic, marinas and a simulated position — press any reply button and get a proper response back, just as if it were real. Nothing is actually transmitted.

AIS

Live AIS & collision alerts

Live AIS/GPS tracking with CPA/TCPA collision alerts, so you're still watching traffic while you're on the radio.

INT

Vessel interception

Engine trouble and their AIS is still on? Tap them on the chart or search by name, MMSI or callsign, and it plots a live intercept course — not to where they are, but to where you'll actually meet, recalculated as both your speeds change. Can't catch them on a direct course? It tells you straight away, before you waste fuel finding out yourself.

CHT

Offline nautical charts

Offline charts for UK and Irish waters, with channel names pulled from real seamark data — no signal needed.

SRM

AIS-SRM digital terminal

Turns your tablet into a passive maritime safety receiver — decodes Type 14 broadcast alerts from any nearby vessel and Type 12 messages addressed to your MMSI, then pre-fills a response script, entirely offline.

MOB

Single-handed MOB rescue

If you're sailing solo and go overboard, the boat recognises it's unmanned and automatically broadcasts a VHF Mayday with your beacon's position — extending its approximate 2nm range out to your vessel's own VHF radio range, typically up to 15nm.

POS

Map marker finder

Search the chart for buoys, marks and other charted features, and jump straight to them on the map.

BTN

Custom buttons

Add your own call buttons for any scenario you need, alongside the built-in ones — set the icon, label and script yourself.

RPL

Custom quick replies

Each button comes with its own set of suggested replies matched to that call, and you can edit them or add your own.

See the full spec sheet →

How it works

Four steps, calm every time

Pick the scenario

Marina, harbour master, Coastguard, VTS, a lock, or a buddy boat.

Check the wording

An editable, COLREG-aligned script is ready before you press send.

Send it on channel

Tap send and it's read aloud over your radio, clearly.

Stay aware

Live AIS keeps watching CPA/TCPA risk in the background while you call.

Early look

Single-handed MOB

Single-handed, and no one left to call it in

Solo sailor overboard — no one left aboard to make the call. The boat recognises it's now unmanned and transmits an automatic VHF Mayday with the beacon's coordinates, reaching boats and stations up to 15nm away, far past the beacon's own approximate 2nm range. Search and Rescue or the Coastguard stay in control throughout, and can silence the loop remotely to free the channel.

Home screen

Main call screen showing nearest ports, nearby vessels, and a confirm-transmission message ready to send — Home screen — nearest ports, vessels in range, and the message ready before you transmit

Reply options screen showing acknowledge and status buttons, plus specific replies like confirm port side to, or starboard side to — Quick replies matched to that call — port-to/starboard-to confirmations here, different for every button, and you can add to or change them

Marker & position lookup and Vessel interception

Offline navigation chart with a buoy selected, showing its name and light characteristics — Offline chart — tap any buoy or mark for its details

Navigation chart showing a marina's full detail card, including harbour master, VTS and facility information — Marina details, pulled straight onto the chart

Plot a reported position screen, entering a distance and compass direction from a named marker such as Q1 buoy — Turn a Mayday position into a fix — "1nm NE of Q1 Buoy" — pick a marker, direction and distance, or just type in lat/lng coordinates

Routing screen showing a heading arrow, turn instruction, speed, distance, bearing and ETA to the plotted position — Routes straight to it — heading, distance, bearing and ETA at a glance

Plot reported position screen showing search results for a tracked vessel by name, with matches for Northern Light, Nordic Reefer and Nordica — Or find them by name, MMSI or callsign — no need to spot them first

Live interception screen showing ON COURSE status, speed, distance, bearing and ETA to the intercept point — Not a straight line to them — a moving intercept point, recalculated as their speed and yours both change, so you get there quicker

Interception screen showing a warning that the target vessel cannot be caught on a direct course even at the user's max hull speed — Can't catch them even at your max hull speed? It tells you honestly — using the top speed you've set in Settings, before you burn fuel finding out the hard way

Enlarged full-screen compass view showing a turn instruction, with a green ring around the arrow indicating live AIS reception from the target vessel — Tap the compass on the map screen to fill the whole screen — the ring around the arrow turns green while AIS is coming in from the vessel, red if it drops out. Tap anywhere to exit back to the chart

Collision alerts (CPA)

Home screen showing a vessel highlighted red with a close CPA warning and a tap to call prompt, along with COLREG alignment and intent buttons — Flags a close-quarters vessel in red, with COLREG calls ready to go — including the vessel name, your vessel name, and closest marker or lat/lng if needed

Navigation chart showing a vessel highlighted red on the map with a CPA warning banner — The same warning, plotted on the chart

Collision Risk relative view over the real chart, showing FJORD BREEZE's projected track, a trial 30 degree port turn opening the CPA to 0.76nm, and a Send course change message button — Collision Risk View — trial a turn at your current speed and see the resulting distance, toggling the chart on or off as you go

The same Collision Risk relative view with the chart toggled off, showing just the two vessels' projected tracks and closing distances — Collision Risk View — trial a turn at your current speed and see the resulting distance, toggling the chart on or off as you go

Settings

Four versions of the same call script side by side: Phonetic and Standard, each shown Not Paced and Paced, with the Paced versions broken into blocks separated by vertical bars — Phonetic and Paced toggle independently in Settings — top row not paced, bottom row paced — and both apply to real live calls too

Pre-Trip Vocal Pacing screen mid-exercise, showing a breathing guide circle prompting Breathe in, the anchor word Mayday, step 1 of 16, and Prev, Pause Guide and Next controls — Pre-Trip Vocal Pacing — a rhythmic breathing guide in Settings to practice relaxed breathing and gentle word blending before you're ever on a live channel

Real screenshots, taken mid-development — some screens are still changing.

Hardware

One cable, for the moment you can't press it yourself

No new transmitter, no new call sign. Everyday calls just need the tablet's speaker held to your radio's mic. The one place hardware comes in is the Single-Handed MOB relay — a Digirig Mobile USB audio interface wired to your existing VHF, so the app can key PTT automatically when there's no one aboard to do it.

Tablet

→

Digirig Mobile

→

K1 cable

→

VHF radio

Currently tested with a Standard Horizon HX891BT handheld. A fixed-mount option is also being explored for the chart table.

Get in touch

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Development notice: VHF Radio Assistant is currently in active development and is not yet available for public deployment. All preview features, scripts, and interface designs are subject to change. This software is intended strictly as a secondary training and preparation aid and does not constitute official maritime safety or navigation advice.