Grey water management is a challenge faced by many vessel operators — especially when fats, oils, and grease (FOG) accumulate in tanks and lines over time. One superyacht recently experienced exactly that issue, with recurring system blockages and performance failures that disrupted onboard operations.
The crew turned to GNC Marine’s GWP Super, and the results were transformational.
A solution was urgently needed. That solution came in the form of GNC Marine’s GWP Super — tested and recommended by GNC Marine partner Noordzee.
During routine operations, the yacht’s engineering crew noticed that grey water was no longer transferring as expected. The transfer pump was running dry, and further inspection revealed the root cause: large amounts of solidified grease and fat floating in the grey water tank. Even after tank sanitation, lingering deposits continued to disrupt performance — especially within the baffle sections and suction point.
To address the problem, the crew began a controlled onboard trial using GWP Super, under guidance from Noordzee — an official partner of GNC Marine.
GWP Super is a biological treatment solution specifically engineered to break down:
Fats, oils, and grease (FOG)
Organic residue and biofilm
Odour-causing buildup
Debris in hard-to-reach tank areas
The product comes in pre-dosed, fully dissolvable bags. Mixed with hot water and poured down a drain connected to the grey water tank, GWP Super is fast, effective, and easy to apply — no need for direct access to the tank.
Following a weekly dosing routine over four weeks, the results were clear:
✅ Improved water transfer and flow performance
✅ Reduced suction point blockages
✅ Fewer alarms from the Hamann system
✅ Cleaner internal tank surfaces, including baffles
✅ Noticeable odour reduction
The treatment not only broke down fresh grease buildup — it also loosened and degraded long-trapped deposits in previously unreachable areas of the system. After a final manual clean, the system was fully restored, and GWP Super became part of the yacht’s ongoing maintenance routine.
Fast, effective breakdown of FOG and organic waste
Maintains clean tanks and pipework
Improves system reliability and pump efficiency
Simple, no-hassle application
Trusted by professionals and tested by GNC Marine partners
This case study, conducted by Noordzee, demonstrates how GWP Super delivers real-world results onboard demanding marine systems — restoring functionality and preventing future build-up.
Looking for a powerful and easy-to-use grey water treatment solution?
Explore GNC Marine’s full range here.
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