Mermaid M9 – Cool & Reverse Cycle Unit 9,000 BTU’s 110V

The Mermaid M9 Cool & Reverse Cycle in 110V trim brings the same 9,000 BTU cooling and heating combination to boats without 220V or 230V shore power. It’s built to handle about 800 cubic feet of cabin space, cooling boats up to roughly 30 feet as a cruiser or 32 feet as a sailboat, and one verified owner review specifically notes it replaced a 16,000 BTU unit and still handled a Catalina 30 without issue.

Why Choose the Mermaid M9 Reverse Cycle (110V)

This is the standard-voltage option for most US boats running dockside 110V power, and it avoids the added electrical complexity of stepping up to 220V or 230V circuits. One documented customer review describes downsizing from a 16,000 BTU unit to this 9,000 BTU model and still cooling a Catalina 30 comfortably on the hottest days, while noting quieter operation than the unit it replaced.

Boats without a heating need — pure warm-climate cruising, for instance — may not need the reverse cycle function at all; Mermaid’s Cool Only 110V configuration is a simpler option in that case.

What to Know Before Installing

• Pump is not included and must be purchased separately
• Ducting needs both 6″ and 4″ runs, with at least three 4″ round supply grilles
• Air discharge position must be selected at time of order
• Installation guide and programmable control manual are available as downloads from the manufacturer