Siarach III/Black Tide
Protected Area
Start Point to Plymouth Sound and Eddystone
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) - Siarach III/Black Tide offers some of Cornwall & Devon's richest wreck diving. Water ranges 10-18°C, warmest July, August, September.
The Siarach III, also known as Black Tide, rests at a solid 50 metres, a proper technical dive and a good one for it. This 17-metre fishing vessel sank in 2003 and sits upright, mostly intact, on a silty seabed. You can see the wheelhouse, trawl gear, and even the engine room if you’re comfortable with a penetration dive. Over the years, it’s become home to a surprising amount of life for a relatively young wreck; we’ve spotted conger eels tucked into crevices, some decent-sized pollack hovering above the superstructure, and an interesting array of nudibranchs on the hull. It’s a compelling dive for those seeking deeper wreck exploration, offering more than just a fleeting glimpse of history.
Typical Siarach III/Black Tide Dive Profile
Illustrative profile based on site depth and type. Actual dive profiles vary - always follow your dive computer and training.
Safety Notes
Maximum depth 50m exceeds recreational limits (40m). Technical diving certification and equipment required.
Wreck site - avoid penetration without wreck diving certification. Watch for sharp metal and entanglement hazards.
Always perform a 3-minute safety stop at 5m before surfacing.
Nearest Dive Centres to Siarach III/Black Tide
Dive shops near Siarach III/Black Tide
Sound Diving Limited
Plymouth Diving Centre
Dive Looe
Reviews for Siarach III/Black Tide
Conditions
Ocean conditions, forecast and tides for Siarach III/Black Tide
Siarach III/Black Tide Ocean Conditions
Monthly averages for Siarach III/Black Tide, sourced from Open-Meteo marine data - nearest station: Open-Meteo marine grid (50.44, -2.73) (3km away)
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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