The beach water in Coronado is brown.
But lifeguards told NBC 7, it's not a cause for concern.
The color is part of a seasonal cycle caused by algae bloom often referred to as Red Tide.
“It’s perfectly normal. We see it just about every spring and it’s completely safe for people,” said Coronado Lifeguard Captain Sean Carey.
Carey said the bloom is typically caused by a change in water temperature and is usually smaller.
But as of Wednesday, the brownish tint could be seen in the water as far as the eye could see from the Hotel Del Coronado.
There was a concern the brown water could be caused by sewage problems south in Imperial Beach.
That is not the case, and lifeguards in Coronado said there are no water quality issues.
According to the County of San Diego Department of Environmental Health, water samples taken Monday in Imperial Beach indicate bacteria levels are undetectable.
All beach closures have been lifted.
In Coronado, the brown water did not keep tourists from swimming.
“I like knowing that it’s not a sewage problem. I think that nature has its way of handling things, and if it’s an algae bloom, then I would assume that’s what nature wants to have happen,” said Las Vegas resident Kelly Schwarz.