The Eel Grass Girls Mysteries

"Do you know what eel grass is? It’s long, three feet long, thin grass that grows in patches in salt water. The eels hide in it, so it’s creepy to step into it when you’re launching your sailboat into the water. But it’s everywhere along the shore. It can’t be avoided. Just like us – the Eel Grass Girls!" 
So begins Book 1 of the series, Murder Aboard the California Girl.