Captain Mark “Sharky” Alexander started diving nearly 25 years ago as a Public Safety Diver for the Springfield/Sangamon County ESDA rescue squad in Illinois. Sharky is an active recreational, technical, and closed circuit rebreather instructor and expedition leader, arranging and coordinating exploration expeditions around the world.

What To Expect

Arriving for a Mark V dive begins with preparation and communication. Before any gear is touched, the diver and tender review the dive plan, hand signals, and voice communication checks, making sure everyone understands depth, bottom time, and tasks. The sound of air compressors and the presence of the heavy brass helmet set the tone for a serious but exciting experience. Clear communication at this stage builds trust, as the diver relies completely on the surface team once underwater.

Suiting up is a deliberate, methodical process. The diver steps into the canvas or rubber suit while tenders secure the seals, check valves, and connect the air hose and lifeline. Weights are added carefully, followed by the breastplate and finally the iconic Mark V helmet, which is lowered and bolted into place. Each bolt tightened and each check called out confirms readiness. The diver listens to the steady flow of air and tests the voice system, exchanging calm words with the surface crew, knowing that comfort and safety depend on every small detail being done correctly.

The final walk to the ladder is both heavy and ceremonial. With assistance, the diver moves slowly, feeling the weight of the gear and the steady pull of the lines. At the ladder, one last communication check is made before the descent begins. Each step down brings the water higher until the helmet meets the surface and the outside world fades into a muted calm. Guided by the tender’s voice and the steady supply of air, the diver enters the water fully, marking the start of a dive defined by teamwork, tradition, and trust.