The Bear Scouts work on their Scuba-diving Merit Badge, while trying to discover what is causing the pollution in Lake Grizzly that is making Old Jake, a very large catfish, sick.

Brother Bear's been hanging out with a bad bunch of bears called the Too Tall Gang. They're into stealing, lying, cheating, and smoking. But with the help of the rest of the Bear Scouts and a special message from Gramps, Brother finally gets the message--Smoking is addictive. Smoking kills.

Jake, the catfish, shows Brother and Sister Bear how polluted Lake Grizzly is and, as the children explore the lake from the air and under the water, they figure out how to keep the lake clean.

While working on the rock climbing merit badge, the Bear Scouts meet a huge bear named Bigpaw.

Giant Bat Cave has been a home to Bear Country's bats for millions of years. But now crooked Ralph Ripoff wants to turn the cave into an underground theme park] Can the Bear Scouts save the cave before the bats become homeless?