The applications of HP Watermakers desalination systems are always interesting, but understanding the choices and motivations behind those installations is even more valuable in explaining why certain models are preferred over others.

When a yacht owner decides to outfit a boat, they often rely on a consultant capable of interpreting their needs and optimizing them through practical experience. Enrico Tettamanti is exactly that kind of expert, drawing on 250,000 nautical miles sailed across every ocean in the world.

An adventurous life backed by extensive experience

Enrico Tettamanti is now 50 years old, and he spent 25 years living aboard his boats full-time pursuing the Kamana projects: reaching extreme or highly remote destinations by sea. “Extreme made accessible” was the philosophy, with clients joining him in some of the most remote and diverse locations imaginable.

Over the years, he has completed no fewer than three circumnavigations of the globe, mostly through challenging waters such as the Northwest Passage and Arctic routes connecting the Pacific and Atlantic Oceans.

Although he no longer sails full-time, it was a natural progression for him to put his experience to work as a consultant for yacht owners and shipyards. Today, Enrico Tettamanti specializes in project management for fully custom yacht builds, starting from a blank sheet of paper to design and outfit vessels intended for long-range cruising and remote expeditions. He also manages yacht sales and refit projects, while continuing to sail aboard his robust Hallberg-Rassy yacht, naturally equipped with an HP Watermakers SC 140 desalination system.

The importance of having a Watermaker on board

“You don’t need to undertake ocean crossings to appreciate the value of having a watermaker on board,” explains Enrico Tettamanti. “In the past, desalination systems were only installed on yachts of at least 70 feet. Today, they are increasingly requested even on 40-foot boats and smaller.”

“The reason is simple: more and more owners want to spend time away from crowded marinas, preferring peaceful anchorages and secluded bays. In these situations, access to fresh water becomes essential.”

He continues: “Modern sailing yachts, especially high-performance models, feature increasingly aggressive hull lines and shallower interiors, which inevitably reduces available storage space. Freshwater tanks are becoming smaller because interior volume is too valuable. The same issue applies to long-range motor explorers designed for extended autonomy. That’s why having a watermaker on board is becoming less of a luxury and more of a necessity.”

Why HP Watermakers Stand Out for Automation

“One of the most valuable advantages I see in HP Watermakers systems is their automation,” says Enrico Tettamanti. “You don’t have to be an ocean sailor to appreciate it. In fact, weekend boaters may benefit from RP-TRONIC and AMCS even more than long-range cruisers.”

“Those owners typically use their boats intermittently and often without professional crew, making maintenance easier to overlook. In my opinion, these two HP Watermakers features are essential because they ensure the system continues operating correctly even with limited supervision.”

RP-TRONIC is the only automation system for watermakers that eliminates the need for manual pressure adjustments in the engine room by automatically maintaining constant operating pressure. During navigation, seawater salinity and temperature can vary significantly, affecting water density and therefore pressure inside the desalination system. Stable pressure, however, is essential for efficient desalination.

RP-TRONIC solves this issue through a motorized, high-precision micrometric valve that automatically regulates pressure to optimal levels, allowing the watermaker to operate more efficiently and extend its service life over time.

RP-TRONIC works alongside AMCS (Automatic Membrane Conservation System), which automatically preserves the membranes. When a watermaker remains unused for extended periods, bacteria can proliferate on the membrane surfaces, clogging them and reducing production capacity.

AMCS operates in conjunction with the automatic membrane flushing system and RP-TRONIC by automatically dosing sodium metabisulfite during the flushing cycle, significantly extending membrane lifespan.

The Importance of After-Sales Service

“It’s widely recognized that the more a watermaker is used, the better it performs,” says Enrico Tettamanti. “But the average leisure boat spends long periods inactive, typically being used only during the summer season. Weekend owners often leave the dock with full water tanks and have little need to produce additional freshwater during short outings.”

“This intermittent usage can become a reliability issue. The automation systems help tremendously, but unexpected problems can always occur. That’s why efficient, real-time after-sales support from the manufacturer becomes crucial.”

“I’ve experienced this firsthand, and I can confidently say that HP Watermakers’ support service has always been prompt and extremely helpful,” Tettamanti continues. “Even without specific technical expertise, which is actually the norm among most boat owners, their technicians were able to guide me remotely through troubleshooting, identify the issue, and quickly ship replacement parts when necessary.”

“They have the ability to assist anyone, regardless of technical background. Over the phone, they can guide even someone who has never held a screwdriver, thanks also to the simplicity and accessibility of their systems, which are built using top-quality components and materials.”

Choosing the right watermaker

“In general, production capacities between 150 and 300 liters per hour represent the most common range depending on the size of the yacht,” explains Enrico Tettamanti.

“The 220 l/h model is currently the most requested, although on smaller boats other considerations come into play, particularly space constraints and energy consumption.”

“No one likes running the generator overnight, so energy efficiency is always closely monitored. That said, I generally advise against DC-powered watermakers, as they tend to be less reliable.”

“Another important factor is the difference between declared production and actual output. In my direct experience, HP Watermakers systems always deliver the advertised production figures, something that cannot be said for every manufacturer.”

Everything under control from the helm

“An important step toward greener boating is optimizing energy consumption,” recalls Enrico Tettamanti. “From this perspective, it’s essential that all onboard systems communicate efficiently with one another.”

“My advice, both for the watermaker and the generator, is to maximize output in the shortest possible time, which again highlights the importance of real production capacity.”

“To maintain constant control, it’s important to manage all this information directly from the helm station. Thanks to Part-NET, the user interface compatible with Garmin, Raymarine, Furuno, Simrad, B&G, and Lowrance chartplotters, HP Watermakers systems connect directly to onboard displays, allowing users to monitor all system parameters and operations from the chart table.”

“And needless to say, not having to go down to the engine room to check system operation is an enormous convenience.”