In development. The appliance software, the group calls, the logbook chain and the offline install flow are running on a real vessel; sea trials and the subscription service are next. It is not yet available to buy.
Crewwize is offline-first voice conferencing and a tamper-evident ship's logbook for sailing crews. A Raspberry Pi 4 installed on the vessel runs the whole system: it provides the wifi, serves the app to the crew's own phones, forwards the audio for a full-duplex group call of up to eight people, and writes each manoeuvre into an append-only, hash-chained logbook. It works with no internet connection, indefinitely, because nothing it does at sea depends on a server ashore.
Up to eight people in one audio call, hands free, over the boat's own wifi. Under 150 ms mouth-to-ear on the LAN, so "ready — helm's alee" arrives in time to act on. The captain or mate starts the call; the crew join with one tap.
Starting a call for a tack opens the entry; stopping it closes the entry. Position, wind, depth and speed are taken from the boat's instruments where they are available, and who was on the call is recorded with it. One action produces a complete record.
Entries are append-only and hash-chained, and each is signed by the appliance. A correction is a new, linked entry with a reason — never an overwrite. Any retroactive change to the history breaks the chain and is detectable.
The crew install the app from the boat itself: scan the code by the companionway and it comes off the appliance, not an app store. A new crew member can be set up alongside with no mobile data and no internet on the boat's wifi.
The appliance rebroadcasts the boat's instrument data as NMEA 0183 over TCP, so Navionics Boating and other navigation apps on the same wifi show real position, depth, wind and AIS from the vessel's own instruments. No extra hardware.
Every fallback is labelled on screen. If the position came from a phone instead of the instruments, the entry says so. If the clock cannot be verified, the entry says that too. A logbook that quietly guesses is worse than one that admits what it does not know.
The appliance is the whole system. It runs the vessel's wifi, answers DNS for its own name, serves the app over real HTTPS, forwards the call audio, and stores the logbook — all in one program on one small computer, with no internet connection and no other services to keep alive.
The crew join the boat's wifi and open the app. There is nothing to configure and nothing to sign in to except the boat itself. A new crew member signs up on board, the skipper approves them, and they are crew from that moment — at the dock or four hundred miles out.
When the captain taps Tack, two things happen in one action: the call starts and the logbook entry opens. The crew hear the call on their phones. When the captain taps Stop, the entry closes with who was on it, how long it took, and where the boat was.
Each entry is hashed together with the hash of the entry before it, so the log forms a chain. Changing an old entry would change its hash and break every link after it. The appliance signs each entry, and the head of the chain is recorded off the vessel when the boat next has a connection, so even rebuilding the whole chain is detectable.
Nothing is ever overwritten. A correction is a new entry that points at the one it corrects and carries a reason; both stay visible. The record of what was written during the passage and the record of when it was put right are both true, and both are kept.
Every entry records where its facts came from. Position from the instruments is marked differently from position borrowed from an officer's phone. A timestamp the appliance cannot vouch for is labelled unverified rather than dressed up. Export is GPX, CSV, a printable ship's log, or a signed bundle with the full chain for anyone who wants to verify it themselves.
An annual subscription per vessel, paid in advance, with the crew seats included rather than charged per head.
A boat is not a place for an overstated claim. These are the limits, stated plainly, and they will not be softened in a later draft.
Yes. Calls, the logbook, the app install and signing in all run on the appliance aboard the vessel. The only thing that needs an internet connection is renewing the vessel's TLS certificate and subscription, roughly every two to three months, which can be done on a phone hotspot in port.
Eight, in audio, sustained. Each phone sends one stream and receives the others; the appliance forwards packets without decoding them, which is what keeps a Raspberry Pi 4 under half a core and the phones' batteries intact.
No, and that is deliberate — a new crew member must be able to install on the dock with no signal. Android installs a signed package the appliance serves; on iPhone, Safari adds it to the home screen.
A Raspberry Pi 4 with 4 GB of memory or more, installed aboard on a marine 12 V supply, ideally with an external access point for coverage beyond the cockpit. The crew use their own phones.
Yes, read-only, for the voyages you chose to mirror. The cloud never carries call audio and nothing ashore can write to a vessel's logbook.
It is tamper-evident, not certified. Entries are append-only, hash-chained and signed, and the chain head is anchored off the vessel so later alteration is detectable. Regulatory certification as an official flag-state logbook is not claimed.
On Android, yes, while on-watch mode is on. On iPhone the app has to be open — background alerting needs push notifications, and those travel over the internet, which a boat at sea does not have.
No. Crewwize is on-board crew communication. It cannot call another vessel, a coast station or rescue services, and it is not a substitute for VHF, DSC or an EPIRB.
Crewwize is being built and sea-trialled now. If you sail, charter or operate a fleet and want to be part of that, write to [email protected].
Crewwize