HMSM L24

Best months: Jul–Sep

Protected Area

South of Portland

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) - HMSM L24 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 51m

StandoutExceptional marine biodiversity

The HMSM L24 is a proper submarine wreck, sitting upright and mostly intact on the seabed at 51 metres. We’ve always found these old subs particularly compelling; there's something about the enclosed, purposeful design that just speaks to history. Dropping down onto her bow, you can still clearly make out the torpedo tubes, eerie and open. The sheer size of her is impressive, stretching 72 metres, and we love drifting along her length, imagining the tight quarters the crew endured. Over the decades, the L24 has become a significant artificial reef. The hull is coated in dense plumose anemones, their white tentacles swaying in the gentle current, punctuated by bursts of vibrant orange and yellow from jewel anemones. Look for conger eels peering out from open hatches or gaps in the plating; they’re often quite bold here. We’ve seen dogfish tucked into the sand nearby too, sometimes even a startled anglerfish camouflaged against the seabed. This dive is definitely for experienced wreck divers comfortable at depth and with cold water, but for those who are, it’s a truly rewarding journey into a piece of naval history.