THE GULLY: 8-20mts

The dive

The Gully is a named dive on the reef around Inishtooskert Island in the Magharee Islands, off the Maharees peninsula north of Castlegregory, Co. Kerry. Waterworld Dive Centre named it and is the only source of a description: you swim between two cliff faces along the gully, from about 8 m at the top to 20 m, and the centre's own text is explicit that the many cave entrances opening off it can be very dangerous if entered because of swell. It is one of four dives the centre names on this island, with The Point, Pollack Alley and The Ridge Holes all inside about 450 m of this pin, so these are separate routes on one island's reef rather than separate reefs.

The surrounding habitat is documented independently. NPWS designated the Magharee Islands as a Special Area of Conservation for reef, describing Carboniferous limestone islands exposed on their west sides and sheltered on their east, with moderately strong tidal streams between them and reef made of boulder, cobble, pebble and sand over areas of solid bedrock. In the shallower, wave-sheltered parts, mixed kelp forest of Laminaria hyperborea, Saccorhiza polyschides and Laminaria saccharina grows on the larger boulders and bedrock, which is the ground the 8 m end of this dive works through; BioMar's nearest dived station, about 780 m south-east of this pin in the channel by Illaunimmil, found exactly that in May 1996, with Laminaria saccharina the commonest of the three over coarse sand and cobble. Nobody has published a dived survey of the gully itself, and the general character of gully ground in this group, recorded off Gurrig about a kilometre away, is limestone thrown into ridges and furrows with a coarse sandy-gravelly floor, the rock heavily pitted and bored under a cover of red algae.

Waterworld's list names pollack, wrasse, lobster and conger along the gully, sea scorpion and tompot blenny under the ledges, edible sea urchin and fields of anemone, triggerfish in summer, and a large anglerfish at the end of the gully. Occurrence records within 1.5 km support the lobster and the edible sea urchin, and add what a cold-water reef diver spends the dive looking at: elephant hide sponge, boring sponge and several branching sponges on the rock, light-bulb sea squirt, the sea cucumbers Aslia lefevrei and Holothuria forskali, brittlestars, leopard-spotted goby, sea hare and the nudibranchs Antiopella cristata, Polycera kernowensis and Jorunna tomentosa. Grey seal is the most-recorded animal around this pin; bottlenose dolphin and basking shark are both on record nearby.

• A gully swum between two cliff faces, 8 m at the top to 20 m at the bottom
• Cave mouths off the gully wall, to be looked at rather than entered
• Kelp forest of Laminaria hyperborea and Saccorhiza polyschides at the shallow end
• Anglerfish at the end of the gully, and conger, sea scorpion and tompot blenny under the ledges, per the operator
• One of four Waterworld dives on the Inishtooskert reef, all inside about 450 m

Conditions

Limestone reef around an exposed offshore island, kelp forest in the shallows over boulder and bedrock, and a gully cut between cliff faces. Waterworld publishes about 20 m visibility on an average day, 40 m at best and about 7 m at worst across its sites. Water temperature runs 8 C at the start of the season to 17-18 C in July, August and September. Because the islands are exposed on their west sides and sheltered on their east, which side of the group is diveable is decided by the wind on the day, and swell running into the gully is what closes this site rather than current.

On current: The operator's own warning here is about swell rather than current: the cave entrances off the gully are described as very dangerous if entered because of swell, which means the site is surge-driven on the day. NPWS separately records moderately strong tidal streams running between the Magharee Islands. No source publishes slack times or a current rating for the gully itself, so timing is the operator's call.

Best months: Jun, Jul, Aug, Sep