Nautical Unit Converter
Convert between nautical miles, statute miles, kilometres, fathoms, metres, and cable lengths. Includes speed conversions for knots.
Travel & Explore with The Sailor's Knife
Eight nautical tools plus emergency MOB — works without shore power
You need to travel & explore. Navigation and nomad tools for anywhere. The Sailor's Knife delivers 8 purpose-built tools in a single HTML file.
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
How does The Sailor's Knife help me travel & explore?
The Sailor's Knife provides 8 interconnected tools for navigation and nomad tools for anywhere. 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.
Do I need an internet connection to travel & explore with The Sailor's Knife?
No. The Sailor's Knife runs entirely in your browser as a single HTML file. All 8 tools work offline.
What is the difference between The Sailor's Knife and cloud-based alternatives?
Cloud tools store your data on external servers, require subscriptions, and stop working without internet. The Sailor's Knife is a one-time purchase ($39) that runs locally. Your data never leaves your device.
Can I use The Sailor's Knife on multiple devices?
Yes. Once purchased, you can use The Sailor's Knife on any device with a web browser. Copy the HTML file to as many devices as you need.
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No cloud One fileOne-time purchase
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