Meaning 1 ►▼
catching the curl: to catch a wave at the right moment, to ride it when the wave is cresting.
"Totally Ripping: Catching the Curl at Surfing," NY Times 5/23/2003)
Meaning 2 ►▼
to do something at just the right moment
Good timing. You caught the curl. I think your business idea will work. You found a niche in the market.
There are many idioms with "hang" in them. To hang has many meanings, but in the following terms, to hang means to lean or be suspended. These terms are used in surfing and sailing and have become common in every day usage.