N S W E
Bosun BOSUN
AI-powered boat maintenance

Your boat's
first mate
never sleeps.

Upload your manuals. Bosun reads every page, extracts every service interval, and builds a precise maintenance schedule — so nothing gets missed.

Join the Waitlist See how it works
9:41
Today
Sailor Moon
Needs your attention 1
Engines · Port & Stbd
Adjust alternator V-ribbed belt tension
Overdue
Every 250 hours or 1 year, whichever comes first.
SNOOZE
VIEW TASK →
Needs review 3
Engines · Port & Stbd
Adjust valve clearance
New 530 / 50 hrs
Engines · Port & Stbd
Propeller shaft alignment
New 530 / 50 hrs
Fuel · Port & Stbd
Bleed air from fuel system
New 530 hrs
Today
Schedule
Logbook
Manuals
Fleet
The problem

Boats break when
maintenance slips.

Most boat owners are diligent — but tracking a dozen systems, each with different intervals buried across different manuals, is a full-time job. Something always falls through the cracks.

How it works

From cold start to a
full maintenance plan
in minutes.

01 Drop in your manual
Yanmar_4JH45_Service_Manual.pdf
284 pages · 18.4 MB
Victron_MPPT_Manual.pdf
96 pages · 4.1 MB
Drop another PDF here
Bosun AI
reads every page
02 Review & import tasks
Yanmar_4JH45_Manual.pdf
59 tasks

Review each task below. Tap to edit name, system, category or interval.

Engines · Inspection · JH Series
Visual inspection of engine exterior
Fuel · Maintenance · JH Series
Replace the fuel filter element
Interval Every 365 days
System Fuel
Category Maintenance
Engines · Maintenance · JH Series
Replace the lube oil – Engine
Cooling · Maintenance · JH Series
Replace raw water impeller
Bosun reading · Yanmar 4JH45 · Page 42
6.1 PERIODIC MAINTENANCE SCHEDULE
The following intervals must be observed to maintain
warranty coverage and engine longevity.
■ Engine oil & filter: Every 100 hours or 1 year,
whichever comes first. Use SAE 15W-40 CF grade.
Capacity: 5.8L with filter. Drain plug torque: 35 Nm.
Part no. 119305-35170 (filter element)
■ Raw water impeller: Every 200 hours or 2 years.
Inspect for wear; replace if blades are deformed.
Part no. 129470-42510. See Fig. 6-4 for removal.
■ Fuel filter element: Every 200 hours. Bleed air
from system after replacement (see p. 78).
Extracted maintenance tasks
Engine Oil & Filter Change
Every 100 hrs or 1 year · p. 42 · $85 est.
Raw Water Impeller
Every 200 hrs or 2 years · p. 67 · $45 est.
Fuel Filter Replacement
Every 200 hrs · p. 78 · $32 est.
Valve Clearance Check
Every 1,000 hrs · p. 112 · $0 est.
Features

Everything a serious
boat owner needs.

Bosun isn't a generic task list. Every feature is built around how boats actually work.

AI Manual Reading

Every task traced to the exact page in your manual. No guessing — precise extraction from your actual documents.

Yanmar 4JH45p. 42–67
Victron MPPTp. 18–24
Garmin VHFreading…

Alerts That Matter

Overdue jobs surface immediately. Each alert shows the system, how overdue it is, and a one-tap action to start or snooze.

Hours & Cycles Tracking

Log engine hours, generator cycles, and pump run-counts. Bosun calculates exactly when each service interval is due.

Sparklines & Trends

Each system card shows a mini trend of recent service history so you can spot a system getting more attention than usual.

Full Maintenance Schedule

Chronological view grouped by week, urgency, or system. Filter by upcoming, overdue, or completed. Export to PDF.

Parts Lists & Cost Estimates

Every task comes with a parts list and cost estimate from your manual — budget and order before you're in the yard.

Reviews

Trusted by
serious sailors.

★★★★★

"I uploaded my Yanmar manual and within two minutes Bosun had pulled out 23 maintenance tasks I didn't even know existed. It's embarrassing how much I was missing."

MC
Marcus C.
SV Blue Compass · Beneteau 45
★★★★★

"Finally an app that understands boats. Not generic tasks — actual intervals from my actual manuals. The parts cost estimates alone saved me hours before our refit."

SL
Sarah L.
MV Resolute · Nordhavn 40
★★★★★

"We avoided a mid-passage engine failure because Bosun alerted us to an overdue impeller. It's not hyperbole to say this app saved our crossing."

JW
James & Tara W.
SV Meridian · Hallberg-Rassy 42
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