All Hands on Deck: Learning Adventures Aboard Old Ironsides
curriculum home
    Table of Contents > Lesson 9: Dog Watches and Cat-O'-Nine Tails > Can You Fathom This?  
how to use this online curriculum
preview activities
table of contents
video
search
USS Constitution, Johnson



Getting Started    Key Words and Concepts    Glossary    Activities    Recommended Resources     Scuttlebutt

Before assigning this activity, you might explain that a nautical mile is the distance of one minute, or 1/60th of a degree, of the equator’s 360-degree circumference.

Can You Fathom This?
Measuring Nautical Speed and Ocean Depth

Ships record their speed in knots. One knot is the speed of one nautical mile per hour. A nautical mile is 6,076 feet. On land a mile is 5,280 feet. Ocean depth is measured in fathoms, with one fathom equaling six feet. Use this information to solve the problems below.

1. How much longer is a nautical mile than a land mile? 796 feet longer
2. A ship traveling 10 knots is traveling at what speed in land miles per hour? 11.5 miles per hour
3. A sunken ship buried at a depth of 48 fathoms is how many feet below the surface of the water? 288 feet
4. (a) Some whales are said to dive half a mile below the surface. If the statement is referring to land miles, how many fathoms is this? 440 fathoms
(b) If this statement is referring to nautical miles, how many fathoms is this? 506 1/3 fathoms
  Extra Credit: How did the term knot become used as a measure of speed? From counting the number of knots that ran out in the line tied to the chip log used to measure speed.

Diagram

Have on Hand- photocopies of blank worksheet

Blank Worksheet (pdf)

to top

 
curriculum creditsuss constitution museum homecopyright information uss constitution museum logo