Noah's dad, Paine, is a kind but slightly irresponsible fisherman, passionate about saving the local Florida aquatic life. When Paine discovers that a local businessman is running a scam from his casino boat, he takes the law into his own hands, sinks the boat and ends up in jail. The scam involves releasing the effluent from the boat's toilets directly into the water, to avoid the cost of disposing of it safely. Noah and Abby, his sister, take up the fight on Dad's behalf and enlist the help of Shelly, former girlfriend of Dodgy Businessman. Shelly knows that DB is up to no good and comes up with a plan to prove it. She gets a job as a barmaid back on the casino boat and plans to sneak a huge load of coloured dye into the toilets. Meanwhile...Noah and his sister have never known their paternal grandfather but have always been told that he died in mysterious circumstances in South America. As they delve deeper into the mystery, an elderly stranger turns up and seems to be watching over them, even intervening to save Noah when he's being beaten up by DB's horrible son...On the night planned for Shelly's mission, Noah and Abby are watching from a small rowing boat. Unfortunately they are spotted from the deck of the casino boat by a violent thug who works for DB. As he raises his gun to take a shot at the kids, he is pushed aside by the mysterious old man. When the toilets are flushed that night, the bay turns orange, the coastguard are called and the terrible scam revealed. Dad gets let out of prison and of course the stranger turns out to be their grandpa!