Every muster session run from The Muster App is recorded automatically. The iPad captures continuous audio from the moment the session starts to the moment it ends, merges in any VoIP call audio along the way, and uploads the finished file to the admin panel for playback during drill debriefs and inspection evidence. You don't start or stop anything manually — when the muster is live, the recording is live.
This article covers what the recording captures, how the iPad shows you it's working, where the file ends up, and how to turn it off if you need to.
The recording bar
As soon as you activate a muster session, the top of the iPad screen transforms into a dedicated recording bar. It replaces the normal page title and shows:
- A pulsing red dot (the "Rec" light — visible across a dark wheelhouse)
- A microphone icon
- The word Recording in bold uppercase
- A live MM:SS timer counting from the moment the session started
The bar stays visible on every tab — Crew, Visitors, Safety, Assets, Muster — so even if the iPad is used for something else mid-drill, the captain always has clear visual confirmation the session is still recording. The whole header picks up a soft pink tint so the urgency reads at a glance.
When the session ends, the bar disappears and the normal page title returns. If audio recording has been disabled for your yacht, the bar doesn't appear at all — the session runs, crew are accounted for, events are logged, but no audio file is captured.
What gets captured
The iPad records whatever its microphone can hear. Typical content:
- The captain's and officers' voices during the muster
- VHF radio traffic if the radio is in the same room
- The ship's alarms going off
- Crew reporting at stations
- PA announcements
- Ambient noise (engine room, weather, helicopter)
Most yachts position the controlling iPad on the bridge or bridge wing, which captures the primary incident command audio. The recording is mono, uncompressed at capture time, and compressed to M4A/AAC before upload so file sizes stay manageable (roughly 1–2 MB per minute).
VoIP calls are merged into the recording
When you tap Fire, DPA or Medical from the iPad's emergency contact buttons during a muster, both sides of the VoIP call are captured into the same recording file as the rest of the session. The call audio is mixed with the microphone input so you hear both the captain's side of the conversation and the remote party's side in the playback, seamlessly interleaved with the surrounding muster audio.
Technically the iPad splits the session into segments around each call — pre-call mic audio, call audio, post-call mic audio — and stitches them back together in chronological order when the session completes. You don't see any of this; you just get one continuous file on the server. The handoff is seamless in both directions, so a conversation that starts before a call and continues after it plays back as one uninterrupted thread.
Where the file ends up
When the session is completed on the iPad, the recording finalises and uploads to the admin panel. You'll find it under Muster Sessions in the sidebar:
- Click the session in the list to open its detail panel
- Scroll to the Recordings section
- Recordings are grouped by the iPad that made them (if multiple iPads recorded the same session) and have pre-signed download links
- Click the file name to stream it in the browser, or download to save locally
Recordings are kept indefinitely by default. Audio is stored encrypted at rest in secure cloud storage, and the download links are short-lived (auto-signed per-request) so the files can't be shared publicly by accident.
Offline recording
If the iPad loses connectivity mid-session, audio continues being written to the iPad's local storage. When the iPad reconnects, the recording is uploaded to the server automatically. You don't have to do anything, and no audio is lost — the file is captured locally first, uploaded second.
For sessions that start and end entirely offline, the audio sits on the iPad until the next time it's online. The admin panel shows "Pending upload" on sessions where the recording hasn't been received yet, and the indicator clears the moment the file arrives.
Turning recording off
Audio recording is on by default for every yacht. To turn it off globally, an admin goes to Muster Sessions in the sidebar, opens the Settings tab, and toggles Enable muster audio recording off under the Audio Recording section.
When disabled, future sessions run normally but no audio is captured. The recording bar doesn't appear, no file is generated, and the Recordings section in the session detail is empty. You can turn it back on at any time — it takes effect on the next session, not the one currently running.
Most yachts leave it on. The audio is too useful for drill debriefs, ISM inspections, and real-incident reconstruction to give up lightly. But some flag states or charter contracts may require crew consent for recording — turn it off if your yacht's situation calls for that.
Why the recording matters
The audio file transforms a muster from a head count into an auditable event:
- Drill debriefs — sit down with the senior officers and listen to the first ten minutes. You'll hear exactly what was clearly communicated, what was confused, and where the crew hesitated. This level of detail is impossible to reconstruct from a paper log.
- Real emergency investigation — if something real happens, the audio is the most accurate record of who said what, when. Your DPA, your insurer and your flag state will all want it.
- ISM Code evidence — playing an audio recording of a real drill is more convincing than showing a signed form. Inspectors who want to verify your drills actually happen can listen to the tapes.
- Training — new crew can listen to past drill recordings to hear how the bridge sounds during a session before they ever experience one themselves.
What's next
For the admin panel review flow — where you actually listen to recordings — see Reviewing past muster sessions. For the live session UX that triggers the recording, see Muster Control (iPad).