top of page
Writer's pictureThomas Flinskau

Watermaker for boat Showdown: Seawater Pro vs. Rainman Watermakers

Choosing the right watermaker for your boat is crucial for ensuring a comfortable and self-sufficient voyage. Here's a detailed comparison of two of the most popular options: the Seawater Pro AC 110-220 Volt 970 Watts, 40 GPH Dual Membrane and the Rainman Naked High Output RO 100-140 lph 2 x 40″ RO Membranes.


watermaker
Watermaker for your boat

Watermaker Capacity and Production for boat:

  • Freshwater Output: The Seawater Pro boasts a production rate of 40 gallons per hour (GPH), which translates to roughly 151 liters per hour (lph). Rainman's Naked High Output RO falls within a range of 100-140 lph, making Seawater Pro the clear winner in terms of raw production capacity. This is a significant difference, especially for larger boats or those with high water consumption needs.


Power Consumption:

  • Wattage: Seawater Pro draws 970 watts, which is significantly lower than Rainman's 1250 watts steady state power consumption. This difference can be very important, especially if you have limited onboard power generation.


Membrane Configuration:

  • Number of Membranes: Both systems utilize two 40-inch RO membranes. This is a standard configuration for high-output watermakers, and it ensures efficient water production while maximizing filtration capacity.


RO
Rainmans reverse osmosis unit (RO)

Features and Functionality

  • Controls: Seawater Pro offers manual controls, and the same has Rainman, which some users might prefer for their simplicity and ease of troubleshooting. 

  • Automatic Features: Seawater Pro comes with a built-in automatic rinse/run functionality, which helps to extend membrane life and reduce waste water. Rainman offers a optional autoflush system incorporates a solid state programmable timer that will flush your Rainman watermaker after each use and every seven days thereafter.

  • Pre-filters: Both systems likely include pre-filters to remove sediment and protect the RO membranes. However, specific details about the type and capacity of pre-filters might differ.

autoflush
Rainmans optional autoflus unit


Additional Considerations for watermaker for boat:

  • Size and Weight: Information on the size and weight of both watermakers is unavailable. However, given the generally larger capacity of Seawater Pro, it might have a slightly bigger footprint. This is an important factor for boats with limited space.

  • Installation: Seawater Pro claims easy installation with everything included. Rainman offers an optional easy mounting kit, but the standard plumbing kit might require separate purchase.

  • Warranty: Seawater Pro comes backed with a 2 year warranty. Rainman units and RO membrane units are guaranteed to be free of manufacturer defects and to perform within the published specifications for a period of two years from the date of shipment to the original purchaser. It's crucial to check the warranty duration and coverage before making a purchase.


Cost of Watermaker for boat:

  • Pricing: The Seawater Pro with a white control panel costs at this time $3 995,00USD. Rainman  with a control panel (without autoflush) costs at this time $5 604,00USD.

This makes the Seawater Pro unit about 30% less expensive than the Rainman. It's essential to contact the respective manufacturers or retailers for accurate pricing details.


The Verdict between Seawater Pro and Rainman watermaker for boat:

Here's a breakdown to help you decide:

  • Choose Seawater Pro if: You prioritize high water production capacity (40 GPH), lower power consumption, and appreciate automatic rinse/run functionality and you will get it to a significant lower price..

  • Choose Rainman Naked High Output RO if: potentially smaller size are crucial factors.


Additional Factors to Consider when choosing watermaker for boat:

  • Brand Reputation: Research online reviews and user experiences with both brands to get a sense of their reliability and customer service.

  • Availability of Spare Parts: Ensure that spare parts for your chosen watermaker are readily available, especially if you're planning extended voyages.

  • Maintenance Requirements: Compare the maintenance schedules and complexity of each watermaker. Choose the one that best suits your level of technical expertise and available time for maintenance.


By carefully considering these factors alongside this comparison, you can make an informed decision and select the watermaker for your boat that best suits your specific needs and sailing lifestyle.









bottom of page