History of sports inventions: Identify the item invented by Ralph Samuelson at age 18 in 1922. Full question: Ralph Samuelson was only 18 when he invented this sporting item in 1922. What was that? Choose the correct option.

Given data

• Inventor: Ralph Samuelson.
• Year: 1922; age 18.
• Task: Identify the sporting item he invented.

Concept / Approach
Ralph Samuelson is widely credited with inventing water skiing in 1922 on Lake Pepin, Minnesota, by experimenting with boards and a clothesline as a tow rope.

Option analysis
Water skis — Correct. Matches the 1922 Lake Pepin experiments. Snowboard — A much later 20th-century development. Hang glider — Modern hang gliding took off mid-20th century, unrelated to Samuelson. Surf leash — Gained traction in the late 1960s–70s.

Common pitfalls
Confusing Samuelson's 1922 lake experiments with later board sports.

Final Answer
Water skis.