TSK (Tauchschule Kümpeli) is a PADI 5-Star Instructor Development Center (certified since 2008) with locations in Zürich (Stauffacherquai 54) and Bern (Könizstrasse 157), plus TSK Ticino. The school offers courses across all levels: Kids & Juniors, Beginner, Advanced, Specialty, Professional, Technical Diving, Freediving, Swimming, and Mermaiding. Dive travel departures cover the Mediterranean, Red Sea, Indo-Pacific, Caribbean, and cold-water destinations. The Zürich and Bern shops sell equipment from brands including Mares, Scubapro, and Fourth Element, with workshop service and gear rental. TSK organises annual lake clean-up events and operates as a climate-neutral business.