Nautical Unit Converter
Convert between nautical miles, statute miles, kilometres, fathoms, metres, and cable lengths. Includes speed conversions for knots.
The Sailor's Knife for Traveler / Nomads
Eight nautical tools plus emergency MOB — works without shore power
Tools that work anywhere — even off-grid. The Sailor's Knife gives traveler / nomads 8 specialised tools in a single HTML file that runs entirely offline.
The Sailor's Knife v2.0 gives mariners eight practical tools and an emergency system in a single HTML file. Convert nautical units, reference the Beaufort wind scale with sea state descriptions, calculate tide heights using the rule of twelfths, compute compass corrections for variation and deviation, browse knot guides by category, reference IALA Region A and B buoyage systems, plot dead reckoning legs with leeway and tidal set on a dynamic chart, and check sunrise, sunset, twilight times, and moon phase for any date and position. The MOB button instantly logs your position and starts a timer. Everything works completely offline — perfect for passages, anchorages, and ocean crossings.
WHAT'S INSIDE
8 tools in a single HTML file
Beaufort Scale Reference
Complete Beaufort wind scale from 0 to 12 with wind speed ranges, sea state descriptions, wave heights, and land condition indicators.
Tide Calculator
Estimate tide heights between high and low water using the rule of twelfths. Enter known tide times and heights for your port.
Compass Deviation Calculator
Apply variation and deviation corrections to convert between true, magnetic, and compass bearings. Includes the TVMDC mnemonic.
HOW IT WORKS
Three steps. No setup.
1
Download the file
Purchase The Sailor's Knife and download a single HTML file. No installer, no account, no setup.
2
Open in any browser
Double-click to open in Chrome, Firefox, Safari, or Edge. Works on any operating system.
3
Start working
Your data stays in your browser's local storage. Nothing is uploaded. Ever.
COMPLIANCE & GEOGRAPHY
Global
Works in any country. No server dependency, no regional restrictions.
FAQ
Frequently Asked Questions
Why should Traveler / Nomads use The Sailor's Knife?
The Sailor's Knife is built for traveler / nomads who need maritime & navigation tools without cloud dependencies. Nautical unit converter, Beaufort scale, tide calculator, compass deviation, knot reference, buoyage systems, dead reckoning plotter, and celestial almanac — plus a Man Overboard emergency button. Your chart table in a file.
Does The Sailor's Knife work offline?
Yes. The Sailor's Knife is a single HTML file that runs entirely in your browser. No internet connection required. Your data never leaves your machine.
Is The Sailor's Knife a subscription?
No. The Sailor's Knife is a one-time purchase ($39). No monthly fees, no renewals, no price increases.
What tools are included in The Sailor's Knife?
The Sailor's Knife includes 8 tools: Nautical Unit Converter, Beaufort Scale Reference, Tide Calculator, Compass Deviation Calculator, Knot Reference Guide, Buoyage System Reference, DR Plot, Astro Almanac. All accessible from a single HTML file.
Can I try The Sailor's Knife before buying?
Yes. Every product page includes an interactive demo you can try in your browser. No signup required.
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No cloud One fileOne-time purchase
Get The Sailor's Knife — $39Sovereignty as a Service