Sidemount + rebreathers = the modern cave diver's playground. In this episode, Joe sits down with cardiologist, tech instructor, and KISS instructor trainer Dr. Doug Ebersole to unpack the design, history, and real-world use of KISS's two sidemount rebreathers: the Sidekick and the Sidewinder. Doug walks through how the original Sidekick evolved from a semi-closed cave exploration tool into a full CCR, and how a custom project for a double-amputee Marine, Josh Houghtaling, led to the creation of the Sidewinder—now one of the most popular sidemount CCRs in the cave community. You'll hear how each unit is configured, how counterlung placement impacts work of breathing, what's involved in trimming and weighting, and when you might choose a Sidekick over a Sidewinder for extreme restrictions. Doug also shares how some divers use the Sidewinder as a bailout CCR or even convert it into a lightweight "backwinder" for long recreational boat dives. If you're a cave or tech diver eyeing sidemount rebreathers—or trying to decide which KISS chassis matches your mission—this episode will give you a clear, practical comparison from someone who teaches and dives both.