Manatee startles swimmers at Indian Rocks Beach

A stealthy manatee that's earned the nickname Boo was at it again this week. 

See Through Canoe's Michael McCarthy has captured video of Boo sneaking up on beachgoers before. 

This time, the sea cow set his sights on a couple of ladies relaxing near the shore.

One of the women spots Boo and then dips her head under the water to confirm her eyes aren't playing tricks.

That's when she and her friend begin swimming toward the shore.

McCarthy noted Boo's back is noticeably clear of identifiable markings, which are typical of adult manatees. The markings come from being hit by boats and sometimes become a way for researchers to identify manatees that frequent certain areas.