The RNLI volunteer lifeboat crew were alerted that a 16ft speed boat was adrift at the most northern part of the lake near Portumna.
The casualties had apparently been wake boarding when their vessel suffered engine failure.
The RNLI crew launched shortly after 6pm and reached the speed boat at 6.30.
All three people on board were unharmed but were feeling cold. They were provided with blankets and told to wrap up and sit in a huddle at the bow of their boat.
The lifeboat crew set up an alongside tow and made way to Terryglass Harbour where they arrived safely at 7pm.
Jeremy Freeman, Deputy Launching Authority at Lough Derg RNLI advises boat users ‘to dress appropriately for winter weather and water temperatures. Make sure your engines are serviced and always carry sufficient life jackets for everyone on board and ensure that they are worn’.
