Saidul Islam BhuiyanScalable Enterprise Software Engineering Book a call

Case study

Ovue ANCORE: crew wearables and AI that work with no internet at sea

A Kotlin Bluetooth module, an offline upload queue, Gemini insights and a shore portal, built in a small team.

By Saidul Islam Bhuiyan, founder and principal engineer · Published 3 November 2026

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In short

Ovue’s maritime product, ANCORE, supports seafarers who spend months on board with little or no internet. Working as a senior engineer in a small team, Saidul built the Android Bluetooth layer for crew smartwatches, an offline queue that sends small daily snapshots when the ship gets a connection, Gemini health insights behind a safety check, and the BioVue portal for shore teams. The crew modules were delivered for the ANCORE pilot in September 2026.

Client
Ovue (ANCORE and BioVue)
Role
Senior Engineer in a small team
Sector
Maritime crew wellbeing
Delivered
ANCORE pilot, September 2026
Stack
Kotlin, React Native, Node.js, Gemini

Maritime wellbeing · Wearables

Ovue ANCORE
 www.ovue.ai ↗

Senior Engineer in a small team

Crew health data that keeps flowing with no internet at sea.

Context

Seafarers spend three to seven months at a time on board, often with little or no internet. Crew wear a smartwatch and use a mobile app, while crewing, HR and QHSE teams ashore work in the BioVue portal.

Constraints
  • Had to run on a phone and a low-cost wearable
  • Had to keep collecting data with no signal
  • Had to send as little as possible over slow, expensive ship connections
Key engineering decisions
  • A Kotlin Expo native module wraps the watch vendor’s Bluetooth LE SDK
  • All GATT calls go through one serialized queue, and dropped links reconnect with backoff and jitter
  • A foreground service keeps sync running, and a low-power scan wakes the app when the watch is back in range
  • An offline queue sends small daily snapshots whenever the ship gets a connection
  • Gemini health insights pass a server side safety check before a seafarer sees them
  • CrediVault reads medical certificates with Gemini, and the seafarer confirms each value
  • Speak Up routes confidential reports to the Captain, DPA or QHSE
  • The BioVue shore portal covers vessels, personnel, training and certificate review
Results
Offlinewatch to phone sync needs no internet
2crew modules delivered for the pilot
Sept 2026ANCORE pilot delivery
Simplified Ovue ANCORE data flow: the smartwatch syncs to the phone over Bluetooth, readings wait in an offline queue, and small snapshots reach the cloud API and shore portal when the ship has a connection.Smartwatchhealth readingson the wristPhone appBluetooth LE syncno internet neededOffline queuestored on devicesmall daily snapshotsShip linkslow and expensivewhen availableCloud APICloud Run, PostgresGemini insightsBioVueshore teamscrew and certificates
Simplified Ovue ANCORE data flow: the smartwatch syncs to the phone over Bluetooth, readings wait in an offline queue, and small snapshots reach the cloud API and shore portal when the ship has a connection.
KotlinBluetooth LEReact NativeTypeScriptNode.jsPostgreSQLPrismaGeminiCloud Run

Lessons for your project

What carries over to other systems

  • Store first, upload laterIf the device is the source of truth until a link appears, a dropped connection stops being an emergency.
  • Pay for every byteSmall daily snapshots and uploading only new data respect how slow and costly ship connections are.
  • Serialize Bluetooth callsOne GATT queue with backoff reconnects avoids the overlapping calls that make wearable links unreliable.
  • Keep people in control of AIA safety check on insights, and a seafarer confirming each certificate value, keep mistakes from reaching the record.
Maritime, transport and logistics →IoT and Bluetooth →BRTC case study →

Questions

Common questions

Anything else is easier to answer on a short call.

How do you sync wearable data at sea with no internet?

The watch syncs to the phone over Bluetooth, which needs no internet. Readings are stored on the phone and sent as small daily snapshots through an offline queue whenever the ship gets a connection.

What did you build on this project?

In a small team, Saidul built the Android Bluetooth module, health history screens, the offline upload queue, Gemini insights with their safety check, CrediVault, Speak Up, and the BioVue admin portal.

Can you build a crew or vessel app for us?

Yes. It starts with a 1–2 week discovery and architecture sprint, priced at $1,000 to $2,000, that maps your crew workflows, devices and connectivity limits.

Tell us what you need to build or scale.

Engagements start with a 1–2 week discovery sprint, $1,000 to $2,000. Email

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