First, have everyone climb onto the upturned hull of the boat to get out of the energy-sapping cold water. Most boats will float for a long time after they have been capsized, unless there is a hole in the hull somewhere. If there is a hole, the buoyant bubble of air under the hull will be leaking out and the craft will sink. Since you all have life jackets on and at least a temporary vessel to cling to, drowning isn't your biggest problem--hypothermia, however, is. Hypothermia can occur in 90-degree water, it just takes several days. In colder water, however, symptoms of exposure can occur in minutes.