A diver’s hot water system is essential for maintaining body temperature in challenging underwater environments. As a diver descends, so then does the water temperature their in, requiring reliable systems for temperature regulation.
Custom Design & Fabrication Ltd. (CDF), Deptford, New Jersey, showcased their hot water systems at this year’s International WorkBoat Show, located in the Underwater Intervention Hall.
Brian Simmons, senior technician at CDF spoke to the range of uses their water systems facilitate, as well as the geographic range that they cover. Simmons, who has extensive experience in designing and maintaining hot water systems for divers and underwater contractors, detailed the diverse applications of their products. "We make hot water heaters," he said plainly, underscoring the company's sole focus on delivering practical and effective solutions.
Simmons explained that the company’s heaters are used in various underwater tasks, from husbandry work on submarines to underwater construction, such as driving piles, repairing boats, and working on dams and bridges. "We have heaters on six out of seven continents," Simmons noted, listing locations that span the globe: from the North and South Poles to South America, Japan, Italy, Scotland, and beyond. "Anywhere there's underwater construction, our systems are there, keeping divers warm," he added.
Their systems are also increasingly used by military organizations worldwide. “The U.S. military uses this system,” Simmons confirmed. “We're the sole source supplier for their hot water heaters for diving operations.” These systems are used by Navy divers who conduct critical maintenance on submarines and ships, as well as the Seabees—Navy construction specialists—who are involved in underwater construction projects. Simmons also mentioned that the Japanese military and several other international defense forces rely on their products.
One of the standout products is the PHW100/1 system, a compact yet powerful heater designed for a variety of underwater applications. This unit is especially popular for commercial diving operations and rescue teams, such as fire departments and police forces involved in search and rescue missions. “This is the bread and butter for commercial divers,” Simmons said, describing how the system provides a consistent supply of hot water to keep divers comfortable in frigid conditions. Nicknamed the “Mini Monkey”, the 215 lb. 23”x35” hot water system is available in both 110V and 220V versions, depending on the scale of the operation.
For more specialized needs, such as saturation diving—where divers are submerged for extended periods in deep waters—the company offers the 1M system, capable of producing up to 1 million BTUs of heat. Originally designed for the Divers Academy in New Jersey, this system is now used for high-pressure, deep-sea diving operations. “It’s made for those going down in the bell,” Simmons explained, referring to the equipment that divers use when working in deep-sea environments.
Beyond just providing hot water, CDF places a strong emphasis on safety. “My main goal is to make sure all the guys stay safe, no matter where they’re working,” Simmons said, highlighting the company's commitment to creating systems that ensure divers remain protected in extreme conditions. Unlike competitor’s products, which can push steam and pose serious risks to divers, CDF’s Monkey Heaters are designed to provide a controlled, consistent supply of warm water, Simmons noted.
“We make water at any temperature you want, and it’s always safe,” he explained. "The last thing you want is steam, which could burn a diver. We make sure our systems don’t create dangerous conditions."
Custom Design and Fabrication’s systems are essential for a wide variety of underwater construction projects. The company works closely with contractors involved in bridge and dam repairs, underwater pipeline installation, and other submerged infrastructure tasks. "Most of our clients are underwater construction companies," Simmons said. "They need reliable hot water to keep their divers working safely and efficiently."
As the demand for their systems continues to grow, Simmons travels regularly across the country, providing training and maintenance support for military bases and commercial operations. "I teach guys how the system works, how to operate it, and how to fix it if it breaks down," he said. "I want to make sure they're ready for anything."
Custom Design and Fabrication, with their specialized hot water heating systems, provides a top of the line product to those working in some of the most challenging and dangerous environments on Earth. Whether it's the military diving to repair submarines, commercial contractors fixing underwater pipelines, or rescue teams operating in icy conditions, their products are a reliable and trusted solution.
