4m
    Cornwall & Devon, United Kingdom
    Severn Estuary

    MERCIA

    Best months: Jul–Sep

    Protected Area

    Severn Estuary

    Why dive here

    With 176+ marine species recorded in the area - including blue sharks, dolphins, dwarf minke whales, humpback whales and ocean sunfish (mola mola) - MERCIA offers some of Cornwall & Devon's richest wreck diving. Water ranges 10-18°C, warmest July, August, September.

    Best timeJul–Sep
    WetsuitA 5mm wetsuit
    Marine lifeBlue Sharks, Dolphins, Dwarf Minke Whales, Humpback Whales and Ocean Sunfish (Mola Mola) · 176+ species recorded
    Water10-18°C · warmest July, August, September
    CharacterWreck dive · max 4m
    StandoutExceptional marine biodiversity

    The Mercia, a tug sunk by a mine in 1942, sits in just 4m of water, making it a fantastic, shallow dive for almost anyone. We love it because it’s a proper wreck, not just a pile of rubble, and the sheer volume of life that’s made it home is incredible. You’ll find schools of pollack hanging in the superstructure, conger eels tucked into every crevice, and the whole wreck is encrusted with plumose anemones, especially on the deeper side. Visibility here can be a bit variable, but on a good day, with the sun filtering through the shallows, the light play on the wreck is beautiful. We'd suggest timing your dive for high slack water to avoid any current and maximise your bottom time poking around the engine room and the bow. It’s perfect for extended exploration, photography, or even just a leisurely drift over the deck. Our favourite aspect is the sheer density of colour from the anemones and jewel anemones – it transforms the wreck into a vibrant, living reef.

    Typical MERCIA Dive Profile

    5mSafety Stop0m4m max~60 min estimated bottom time

    Illustrative profile based on site depth and type. Actual dive profiles vary - always follow your dive computer and training.

    Safety Notes

    Wreck site - avoid penetration without wreck diving certification. Watch for sharp metal and entanglement hazards.

    Today06:2917:2911h 0m daylightGolden hour 16:43

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    Conditions

    Ocean conditions, forecast and tides for MERCIA

    MERCIA Ocean Conditions

    Monthly averages for MERCIA, sourced from Open-Meteo marine data - nearest station: Open-Meteo marine grid (50.44, -2.73) (3km away)

    ExcellentGreatGoodFairPoor★Best monthsThis month

    October Averages

    Sea Temperature

    17°C

    62°F · Range: 15.1–17.5°C

    Air Temperature

    13°C

    56°F

    Wind Speed

    8.14 m/s

    15.8 knots

    Atmospheric Pressure

    1011 hPa

    Based on 4 years of monitoring data · Data sources: Open-Meteo marine data

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