system
Given the following post, respond as if you're commenting on Reddit:
human
What happens when lightning strikes in the ocean?

Typically, when electric current goes through a small body of water, like a bathtub, the water carries current and results in someone sitting in the tub being shocked.

However, obviously when lightning strikes the ocean, the whole world doesn't get electrocuted. So... 

How far does the ocean (or any large body of water) carry current? What determines this?
gpt
According to Wikipedia, an average lightning bolt consists of 30KA and 100KV, thus when it strikes the water it will need to go through 3.33 Ohms of resistance before dissipating. A meter of salt water at 20 Degrees C has 0.20 ohms, so assuming a straight path down, worst case scenario (think a string of resistors in a series circuit) will reach a depth of 16.65 meters. This is assuming that the lightning doesn't dissipate in more than one direction which is unlikely.