Built and owned by Island Adventures, St. Thomas

Find the cause, not just the symptom.

EngineWatch puts the morning checklist your crew already does next to live data from every Yanmar inboard in the fleet. It tracks both across days and works out the most likely cause of a problem, ranked, with the evidence behind it and the first thing to check.

See how it diagnoses See the hardware

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Port rpm 2,800

Port coolant 175°F

Stbd coolant 182°F

Oil pressure 52 psi

House bank 14.1 V

Engine hours 2,152.4

Fault codes None

Impeller Due in 42 hrs

Morning check Logged 7:12 AM

Coolant added this week 0 oz

Your morning checklist is the best engine data you have

Your crew already checks oil, coolant, the belt, the alternator, the Racor, oil pressure at 1200 rpm and voltage every morning. On paper, that ends up in a binder. In EngineWatch, every answer is logged against that engine, lined up with its sensor readings, and compared day to day. The patterns point to the cause.

Starboard engineOne week of morning checks and sensor readings

Morning checklistEngine sensorFlagged

EngineWatch diagnosis

Not enough data yet

Confidence

–

Evidence

Ruled out

Ranked causes

Example cases built from the Island Adventures morning checklist. Hover an evidence line to see the entries behind it.

Every line on the checklist feeds the diagnosis

Engine oil level, oil added: Oil use per engine hour. Rising use points to a leak or wear.
Coolant, coolant added: Coolant loss over time. Separates a leak from a raw-water cooling problem.
Fan belt, wiggle alternator: Belt and mount condition, matched against charging voltage.
Transmission oil: Gearbox fluid use, tied to the leak check at the back of the engine.
Drain 1 oz from Racor: Water or debris in the fuel, and whether it shows on one engine or both.
Fuel tank level: Fuel burn per engine hour, and which fill a fuel problem started after.
Leaks, front and back: Where a leak is, which narrows it down to a few parts.
Oil pressure at 1200 rpm: Same rpm every morning, so a slow drop shows as a trend. A sudden drop often means the sender.
Voltage, port and starboard: Charging health per engine, compared side to side.
Steering fluid: Monthly level, so a slow steering leak shows up over months.
Bilge and engine alarm checks: Confirms the alarms work, logged by date and crew member.
Fluids added, and how much: The most useful line on the sheet. Small amounts every day add up to a diagnosis.

There’s real hardware on the boat

A small gateway mounts next to the engine and plugs into its data output. It only listens. Here’s what an install looks like.

In the engine room

A Yanmar inboard as it sits today. Nothing on the engine gets modified.

0:00 / 0:16

Illustration. Final gateway design and mounting hardware may differ.

A twin-engine boat, watched in real time

Simulated data. Starboard coolant creeps above its own normal while port holds steady. No alarm would trip. EngineWatch works out why.

Demo vessel twin Yanmar inboards, cruising

Port2,140.0 hrs

Coolant temperature at 2,800 rpm

Last 8 trips, against each engine’s own normal range

Port Starboard Normal range

Starboard running hot: likely the raw-water side

+7°F over its usual range at cruising rpm, rising across 5 trips. Port at the same rpm is unchanged. Morning checks show no coolant added this week, so it isn’t coolant loss.

Checks to run, most likely first:

Raw-water strainer for debris
Impeller for missing or cracked vanes
Exhaust water flow at idle
Heat exchanger fouling

Based on: coolant temperature trend, port engine comparison, morning checklist.

Starboard2,152.0 hrs

From engine signal to a fix the captain can act on

An alarm tells you something is wrong. EngineWatch is built to tell you what and why, early enough to plan the repair instead of losing a trip to it.

1

Connect

A small onboard gateway reads what the engine already reports. Electronic Yanmars connect through their digital output. Mechanical engines get an adapter and a few added sensors.
2

Log the morning check

The crew runs the same checklist on a phone: fluid levels, belt, alternator, Racor, leaks, oil pressure and voltage at 1200 rpm, and anything added.
3

Learn normal

Each engine gets its own baseline across rpm bands and conditions, plus how much oil and coolant it normally uses.
4

Find the cause

Sensor trends, checklist answers and service history are compared across days. A few ounces of coolant here, a few degrees there, add up to a ranked list of causes with the evidence shown.
5

Fix it and confirm

The repair is logged, and EngineWatch checks that the readings and the morning checks actually returned to normal.

Ask it what’s wrong

Pick a symptom. EngineWatch answers from the engine’s readings, the crew’s morning checks and the manual for that model, ranks the likely causes, and tells you what to check first.

Example responses for the demo vessel. Real answers depend on the engine model and its data.

Why is the starboard engine running hotter?

Built for Yanmar inboards, old and new

Each supported model gets its own profile: manuals, limits, service intervals and the data it can actually provide. Coverage is validated model by model.

Electronic engines

Reads the data the engine already publishes

How it connects: Yanmar VC20 digital output over NMEA 2000 or J1939
What it reads: Engine data and diagnostic codes the installation provides
What gets added: The EngineWatch gateway. Optional extra sensors.

Mechanical engines

Turns existing gauge signals into data

How it connects: Analog-to-NMEA 2000 adapter on the existing instrument signals
What it reads: rpm, coolant temperature, oil pressure, voltage
What gets added: The gateway, the adapter, and sensors where the engine has none

Core readings

Engine rpm
Coolant temperature
Oil pressure
Battery voltage
Engine hours
Fault codes

With added sensors

Fuel use
Exhaust temperature
Raw-water flow
Vibration

Added where the installation supports it. Each one sharpens diagnosis for a specific set of failures.

Works with no signal

Boats lose signal. Logging, tracking and diagnosis run on the boat itself, and sync to shore whenever there’s a connection.

Shows its evidenceEvery diagnosis lists the readings and checklist entries behind it, and says when it isn’t sure.
Read-onlyEngineWatch listens to the engine. It never sends commands to it.
Factory alarms stayGauges and alarms work as they always have. EngineWatch’s job is figuring out why something is happening.

Shore connectionConnected

DiagnosisRunning onboard

Readings waiting to sync0

Starboard service schedule

Example. Tracked by engine hours and calendar date, whichever comes first.

Raw-water impellerDue in 42 hrs

Oil and filterDue in 70 hrs

Fuel filtersDue in 290 hrs

CoolantDue in 10 months

years running charters in St. Thomas, since 1985

An Island Adventures product

EngineWatch is built and owned by Island Adventures, the family-run charter company behind New Horizons Charters and Breakaway Charters in the U.S. Virgin Islands.

Snorkel tours, private charters, sunset cruises, BVI day trips and cruise ship excursions put real hours on our engines year round. When an engine goes down mid-season, trips get cancelled. We built EngineWatch to see those problems coming on our own fleet first.

Developed and tested on the Island Adventures fleet

Where it stands

Exactly where we are, no overselling.

DoneWorking dashboardEngine profiles, trends, warning limits, service history and guided troubleshooting.
In progressOnboard gatewayTesting continuous data capture on real engines.
NextFleet pilotRunning on the Island Adventures boats in St. Thomas, with the morning checklist logged in the app.
After the pilotOpen to other boatsCharter fleets, private owners and marine service yards.