SeaLogIreland · beginner
A shallow, sheltered seagrass bay near Kinsale where Cork divers do their first open-water dives.
Oysterhaven is a sheltered inlet about 10 km east of Kinsale on the Cork coast, and as a dive site it is honestly a training bay rather than a destination. Discovering Scuba, the PADI operation that uses it, gives an average depth of about 4 m with up to 7 m at high water, and runs its confined-water and open-water skills sessions there. What makes it worth a dive for anyone past their first few is the seagrass: the bay holds an extensive natural bed, which the operator describes as both a carbon sink and a nursery for smaller animals.
The operator names nudibranchs and pipefish in the weed, and dogfish, conger, lobster and crab around it. Records from this patch of coast line up with that: greater pipefish, fifteen-spined stickleback, lesser-spotted dogfish, tompot blenny, leopard-spotted goby, edible and velvet swimming crab, common lobster, spiny spider crab and common prawn in the shallow weed, along with native and Pacific oyster on the bottom.
The bay also matters to Cork divers as a launch point. DUSAC use the slip at Oysterhaven, beside the coast guard station, in preference to the busy pier at Kinsale, and note it is the closer launch for the Ling Rocks - a set of rocky peaks about 9 km south-south-east that top out at 26 m in 55 m of water. The Irish Underwater Council's own south Cork list puts Ballymaccus Bay directly opposite the Oysterhaven slip and calls it a good safe night dive with plenty of life.
One practical warning. In summer the bay is busy on the surface: Oysterhaven Activity Centre runs dinghy sailing, windsurfing, kayaking and paddleboarding out of it, with courses for children from four years old upward. Surface traffic in 4 m of water is a real consideration, so use a marker and stay out of the channel.
Shore entry from the sheltered beach at Oysterhaven, about 10 km from Kinsale - the activity centre on the bay gives its own position as five miles outside Kinsale and fifteen miles from Cork Airport. Clubs launching boats use the slip beside the coast guard station, which DUSAC prefer to the busy Kinsale pier and describe as the closer launch for the Ling Rocks. There is no dive centre on the bay itself.
You can reach the site independently.
No permit or fee for the bay. The seagrass bed is the thing to protect: keep off it, do not anchor into it and control your fins in 4 m of water over a soft bottom. Note separately that the City of Chicago wreck off the west side of the Old Head of Kinsale does require a permit, as an over-100-year-old wreck - that is a different site about 12 km away and the requirement does not apply here.
No source gives a season for the bay and none is set here. Because it is sheltered, Oysterhaven is not weather-gated the way the Atlantic sites in Clare and Kerry are, and the operator uses it for training all through its programme rather than in a summer window. What changes through the year is water temperature, daylight, the surface traffic from the activity centre in the summer months, and the presence of Portuguese man o' war, which is on record for these waters.
Calm, shallow and green rather than blue: a sheltered Cork inlet with a soft, weeded bottom. Depth is around 4 m on average and 7 m at the top of the tide, so the dive changes character with tide state and it is worth timing for high water. Cold-water kit still applies - this is the Celtic Sea, and Irish south-coast temperatures, not the Mediterranean.
On current: No source describes current in the bay; it is a sheltered inlet used precisely because the water is calm. Depth here is driven by tide rather than flow - about 4 m on average, up to 7 m at high water - so the tide state changes the dive more than any stream does. The exposed sites of this coast, the Ling Rocks and the Daunt Rock, do need slack water; Oysterhaven does not.
Shallow. The operator that trains there gives an average of about 4 metres, with up to 7 metres available at high water. That makes tide timing the single biggest variable in the dive. It is a training and macro bay, not a depth site - the deeper diving in this area is offshore at places like the Ling Rocks.
It is one of the better beginner sites on the Cork coast. The bay is sheltered, the water is calm, the maximum is around 7 metres and a PADI operator uses it for both confined-water and open-water skills. Beach entry is easy and the operator describes it as peaceful and child-friendly.
Yes, and it is one of the few sites on this coast where snorkelling is genuinely worthwhile rather than a compromise. The seagrass bed sits in about 4 metres of sheltered water with pipefish and nudibranchs in it. Watch for dinghies, windsurfers and paddleboards from the activity centre, and keep out of the channel.
The seagrass bed is the draw: the operator names nudibranchs and pipefish in it, with dogfish, conger, lobster and crab around the edges. Records for the area add greater pipefish, fifteen-spined stickleback, tompot blenny, leopard-spotted goby, edible and velvet swimming crab, spiny spider crab, common prawn and oysters on the bottom.
It is about 10 km from Kinsale on the Cork south coast - the activity centre on the bay gives five miles from Kinsale and fifteen from Cork Airport. Divers shore-enter from the beach at the head of the bay. Clubs launching boats use the slip beside the coast guard station, which DUSAC prefer to the busy Kinsale pier.
Nothing to do with depth or current. The real issue is summer surface traffic: the activity centre runs dinghy sailing, windsurfing, kayaking and paddleboarding out of the bay, and you will be in 4 metres of water underneath it. Use a surface marker. Portuguese man o' war is also on record in these waters.
No permit or fee applies to the bay. The seagrass bed is worth treating carefully - do not anchor into it and keep your fins off it in shallow water. Separately, the City of Chicago wreck off the Old Head of Kinsale does require a permit because of its age, but that is a different site about 12 km away.
The Irish Underwater Council's own south Cork guide points night divers to Ballymacus Bay, directly opposite the slip in Oysterhaven, and calls it a good safe night dive with plenty of life. The shelter and shallow depth that make the bay a training site are the same qualities that make it work after dark.
| Species | How often | Records |
|---|---|---|
| Necora puber | occasional | 14 |
| Magallana gigas | occasional | 11 |
| Echinus esculentus | occasional | 10 |
| Pollachius pollachius | occasional | 9 |
| Marthasterias glacialis | occasional | 9 |
| Palaemon serratus | occasional | 9 |
| Cancer pagurus | occasional | 9 |
| Taurulus bubalis | occasional | 9 |
| Galathea strigosa | occasional | 8 |
| Obelia geniculata | occasional | 8 |
| Luidia ciliaris | occasional | 7 |
| Homarus gammarus | occasional | 7 |
| Calliostoma zizyphinum | occasional | 7 |
| Cliona celata | occasional | 7 |
| Asterias rubens | occasional | 7 |
| Physalia physalis | occasional | 6 |
| Steromphala cineraria | occasional | 6 |
| Parablennius gattorugine | occasional | 5 |
| Ctenolabrus rupestris | occasional | 5 |
| Labrus bergylta | occasional | 5 |
| Pomatoschistus flavescens | occasional | 5 |
| Carcinus maenas | occasional | 5 |
| Maja squinado | occasional | 5 |
| Pagurus bernhardus | rare | 4 |
| Scyliorhinus canicula | rare | 4 |
| Trisopterus minutus | rare | 4 |
| Aslia lefevrei | rare | 4 |
| Polycera faeroensis | rare | 3 |
| Ascidiella aspersa | rare | 3 |
| Cetorhinus maximus | rare | 3 |
| Crangon crangon | rare | 3 |
| Pawsonia saxicola | rare | 3 |
| Spinachia spinachia | rare | 3 |
| Callionymus lyra | rare | 3 |
| Thorogobius ephippiatus | rare | 3 |
| Syngnathus acus | rare | 3 |
| Aurelia aurita | rare | 3 |
| Phocoena phocoena | rare | 3 |
| Patella pellucida | rare | 3 |
| Tritia reticulata | rare | 3 |
| Clavelina lepadiformis | rare | 2 |
| Galathea squamifera | rare | 2 |
| Hydractinia echinata | rare | 2 |
| Diphasia margareta | rare | 2 |
| Tubularia indivisa | rare | 2 |
| Conger conger | rare | 2 |
| Trisopterus luscus | rare | 2 |
| Lipophrys pholis | rare | 2 |
| Centrolabrus exoletus | rare | 2 |
| Pleuronectes platessa | rare | 2 |
| Zeugopterus punctatus | rare | 2 |
| Hemimycale columella | rare | 2 |
| Halichoerus grypus | rare | 2 |
| Cadlina laevis | rare | 2 |
| Polycera quadrilineata | rare | 2 |
| Amphilectus fucorum | rare | 2 |
| Halichondria (Halichondria) panicea | rare | 2 |
| Atherina presbyter | rare | 2 |
| Symphodus melops | rare | 2 |
| Aplidium punctum | rare | 1 |
The training dive at the mouth of Kinsale harbour: a small island 200 m off the slip, with rock gullies running south-east to about 15 m.
A broken-up Victorian liner scattered in 5-20 m against the western cliffs of the Old Head of Kinsale, with swim-throughs in the wreckage and golf balls in the sand.
A First World War German minelaying submarine lying on her port side in the approaches to Cork Harbour, with her crew and some of her mines still aboard.
A 1900 bucket dredger off Power Head whose hull is gone but whose machinery — chain, sprocket, 2.5 m drive gears, engine, boiler — can still be read on the seabed.
SeaLog imports your dives from your dive computer or Apple Watch, tracks every animal you see, and keeps your logbook safe forever.
Download SeaLog
