The riddle
What Letter Holds the Most Water?
Say it, do not spell it
The name of the letter C is pronounced like the word sea, and like see. The riddle works only by ear. Written as sea or see, the words look nothing like a single letter. Words that sound alike but are spelled differently are homophones, and C, sea and see are a set of three. Said aloud, C is a big body of salt water. The question is searched as "what letter in the alphabet holds the most water", and every version of it leads to the same sound.
How much water is in the sea
The U.S. Geological Survey's Water Science School says the oceans hold about 96.5 percent of all of Earth's water. Lakes, rivers, ice and groundwater share the small remainder, so an answer that stands for the sea is the right size for the question.
Other letters that sound like words
Several letters share a name with a spoken word. B is bee, I is eye, J is jay, Q is queue, T is tea, U is you and Y is why. Each could be built into a question of its own. A group can race to find which letters can be turned into a joke.
Where C sits
C is the third letter of the alphabet, between B and D. For a riddle that also runs on letters, see what has four eyes but cannot see.