Shipping routes, canals and chokepoints
Grade 9 Social Studies Worksheet - Building Confidence

Circle the best answer.
Read this first
Use this
Card A. Compare chart, “Two shipping canals”, columns Canal | Opened | Length | Joins: Suez Canal | 17 November 1869 | 193.3 km | the Mediterranean Sea and the Red Sea; Panama Canal | 15 August 1914 | 82 km | the Atlantic and Pacific oceans. Notes: a canal is a waterway people dig; a strait is a natural narrow channel between two larger bodies of water. A chokepoint is a narrow passage that many ships must use. The Suez Canal is at sea level, with no locks. The Panama Canal’s locks lift ships up to Gatun Lake, 26 m above sea level, and lower them at the other end; a wider third lane of locks opened on 26 June 2016 for larger ships. Without the Panama Canal, ships sail around the southern tip of South America.
Which description of the Suez Canal is right, Ari asks?
- A canal: people dug it, and ships pass without locks at sea level
- A strait: it joins two seas, so it is a natural narrow channel
- A canal with locks that lift ships up to a lake, like Panama’s
- A chokepoint rather than a canal, since many ships must use it
Why does the Panama Canal need locks while the Suez Canal does not, Bo asks?
- Panama climbs to Gatun Lake, 26 m up; Suez stays at sea level
- Panama’s ships are larger, so just locks can hold them in place
- Locks are needed whenever a canal joins two different oceans
- Panama is the longer canal, so it needs more locks to cross
Which canal is longer, and by about how many times, Esme asks?
- Suez, about 1.4 times as long, since 193.3 divided by 82 is about 1.4
- Suez, about 2.4 times as long: 193.3 km against 82 km
- Suez, about 111 times as long, since 193.3 minus 82 is 111
- Panama, since it joins two oceans and so must be longer
A student says: “The Panama Canal is shorter than Suez, so it is easier to cross.” What does Card A support, Jun asks?
- Nothing, since lengths and locks cannot be compared
- Panama is shorter, but it has locks and Suez has none
- Suez is easier because it is longer and so wider
- Panama is easier, since a shorter canal is a quicker crossing
What makes a passage a chokepoint, Kira asks?
- People dug it to join two seas or oceans
- It lifts ships over land with locks and a lake
- It is narrow and many ships must use it
- It is longer than 100 km, which makes ships slow down
Use this
Card B. Two made-up passages. Lantern Channel is a natural channel 12 km wide between two seas, and the ships bound for six northern ports pass through it. Sable Cut was dug across a neck of land in 1950, is 30 km long, has no locks, and ships can instead take another route that is three days longer.
How should Sable Cut be described, Milo asks?
- A canal; it is a chokepoint only if many ships must use it
- A chokepoint, since it is 30 km long and narrow
- A strait, since it joins two seas across a neck of land
- A canal with locks, since a canal cuts through land
A ship has a choice: Sable Cut or a route three days longer. Does that make Sable Cut a chokepoint, Noah asks?
- No: a passage cannot be a chokepoint if ships may take any other route
- No: a chokepoint is one many ships must use, and these ships need not
- Yes: ships choose it to save three days, so it is a chokepoint
- Yes: each canal is a chokepoint, whatever the traffic
Use this
Card A. Compare chart, “Two shipping canals”, columns Canal | Opened | Length | Joins: Suez Canal | 17 November 1869 | 193.3 km | the Mediterranean Sea and the Red Sea; Panama Canal | 15 August 1914 | 82 km | the Atlantic and Pacific oceans. Notes: a canal is a waterway people dig; a strait is a natural narrow channel between two larger bodies of water. A chokepoint is a narrow passage that many ships must use. The Suez Canal is at sea level, with no locks. The Panama Canal’s locks lift ships up to Gatun Lake, 26 m above sea level, and lower them at the other end; a wider third lane of locks opened on 26 June 2016 for larger ships. Without the Panama Canal, ships sail around the southern tip of South America.
The Panama Canal opened a wider third lane of locks in 2016. What does that suggest, Pia asks?
- The older locks could not take the largest ships of 2016
- The older locks were closed in 2016 and replaced
- The canal became longer in 2016, so it could take larger ships
- The older locks were built for ships of 1914, so they are no use now
Ren’s note says: “The Suez Canal has locks that lift ships up 26 m.” Which fix is right?
- Change it: Panama’s locks lift ships 26 m; Suez is at sea level
- Change it: the Suez Canal lowers ships 26 m below sea level
- Leave it: both canals lift ships, one by 26 m and one by less
- Change it: Suez lifts ships to Gatun Lake, 82 m above sea level
Zee’s note says: “A canal and a strait are the same thing.” Which fix is right?
- Leave it: both are narrow waterways between two bodies of water
- Change it: a canal has locks and a strait has no locks
- Change it: people dig a strait; a canal is a natural channel
- Change it: people dig a canal; a strait is a natural channel

