# Tools and Calculators ### TVMDC Explained

TVMDC is a kind of acronym known as a mnemonic initialism. It’s an easy to remember abbreviation word. That means each letter in the acronym stands for the first word in a longer term. It stands for true heading, variation, magnetic heading, deviation, compass heading. Sometimes it will be called true variation magnetic deviation…

### Distance, Speed, Time Worksheet

Coastal Navigation Course Chapter VI Distance, Speed, Time Worksheet Remember: Convert Minutes to Decimals (and back) and Round Answers Distance: Speed: Time: 1. 15.0 nm 8.6 1 hour 45 minutes = 1.75 hours Calculation: D ÷ T = S – 15.0 nm ÷ 1.75 hours = 8.57 kts 2. 12.5 nm 7 kts 1 hour 47… ### How to use dividers

Navigation Tools How to use dividers Using dividers and the latitude scale on your nautical chart, you are able to measure distance in nautical miles. (Remember, do not use longitudes to measure distance. Longitude lines converge at the poles and the distance between them changes relative to your position on the earth.) One minute equals…

### How to use parallel rulers

How to use parallel rulers Parallel rulers are used to plot direction on your nautical chart. They are, essentially, two straight-edges hinged so that they maintain the same angle. By alternating the moving edge, and securely holding down the non-moving edge, you can move the rulers about the chart while still maintaining the same angle….

### Nautical And Statute Mile Calculator And Conversions

Statute Miles vs. Nautical Miles How to convert nautical miles to miles and miles to nautical miles: A statute mile is 5,280 feet in length. A nautical mile is 6,076.11549… feet in length.   To convert from statute to nautical miles a factor of 1.15 is generally used, even though it is not precise. (5,280…

### Speed, Time, Distance Calculations

Time Conversion Enter Time (24 hour=2230) Hr Min Enter End Time: Enter Start Time: Converting to Decimal: Elapsed Time: Speed, Time and Distance Given Two Values, Compute the Third: Speed in knots: Elapsed time (decimal): Distance in nautical miles: 