Stand-Up Paddleboard Gulf Coast posted video Thursday showing an actual line where the brown water ends and green water begins. It's right near the Pleasure Pier.
The Galveston Tourism Board said there's always water like this around the island, you just need to find it.
Around Memorial Day weekend, beachgoers saw the usually chocolate brown water look more clear.
At least one expert theorized that Subtropical Storm Alberto was responsible.
"Today, we have water for the tourists. It's clear. It's coming up from the south, is what it looks like," said Linton. "It's a very short-lived thing. It won't be too much longer. It will go back to what we marine biologists love, which is nutrient rich water for the fish."
READ MORE: That time that Galveston had clear water