Mermaid M3 – 3,500 BTU Marine Air Conditioner Reverse Cycle 120V

Standard 110V shore power is still the most common setup on US boats, and the Mermaid M6 Cool & Reverse Cycle in 110V trim delivers 6,500 BTU of cooling and heating without asking for a voltage upgrade — sized for cruisers up to 27 feet or sailboats up to 30 feet, using the same compact platform found across Mermaid’s 110V lineup.

Why Choose the Mermaid M6 Reverse Cycle (110V)

This is the standard-voltage option for most domestic US boats, avoiding the added electrical complexity of stepping up to 220V or 230V circuits just for a smaller AC unit. Reverse cycle heating means the same unit covers both sides of climate control, which matters for boats used across shoulder seasons rather than pure summer cruising.

Boats without any real heating need might find the Cool Only 110V version of the M6 a simpler, slightly less complex alternative — fewer components generally means fewer things that can eventually require service.

What to Know Before Installing

• Pump is not included and must be purchased separately
• 4″ ducting requires at least two 4″ round supply grilles per Mermaid’s guidance
• The unit can run off a Honda EU1000i portable generator in cool mode, useful for boats without dedicated shore power
• Air discharge position must be selected at the time of order