Punta Marroquí

Two faces of one rock, and you dive whichever the wind allows. The boat ride from Tarifa harbour is short and tells you nothing about the point. The centre reads the tide and the wind that morning and picks Levante, the Mediterranean side, or Poniente, the Atlantic. Below the lip you stay on that face, because the current between them rules out a crossing.

Levante is the wall. A fixed line drops you to around 16 metres, you regroup on the shallow plateau, then run a cliff close to 300 metres long. Its overhangs swallow torchlight. Orange cup coral sheets the rock, morays and conger eels work the cracks, and the fish life thickens at depth, where old iron debris and Roman amphorae and millstones rest near 40 metres. This is the most current-exposed face on the point. Slack means a controlled wall dive; mistime it and half the dive is spent flying along at 15 metres while the current does the swimming.

Poniente is the slow one, a sheltered cliff ledge between 8 and 25 metres fed by nutrient-rich ebb currents that grow things. White, red and yellow gorgonians line a shaded wall, a dark cave holds Dendrophyllia ramea coral, and past the ledge the sand slopes to 45 metres with the anchors on it. Admiralty anchors and a Roman anchor stock are the features that gave this face its local name. Both faces close on the 4-metre plateau for the safety stop, with barracuda overhead.

No other Tarifa site hands you two materially different dives off a single promontory. One side is a deep wall with archaeological clutter on the bottom; the other is one of the richest zones of Isla de Tarifa, a gorgonian garden with the anchors that earn it the name inmersión de las anclas. Centres work both under one dive plan and one mooring rotation, so a single boat day buys the geographic hook of continental Europe's southernmost point and two dives that share almost nothing but the plateau between them.

The water runs cold. There is a temperate-Atlantic feel that catches out divers who came for postcard Mediterranean: cup coral on cool rock, conger eels in deep holes, four nudibranch species off one wall on a good dive. The black seabream on the Poniente face run unusually large. Visibility swings hard day to day. Marroquí pays back the diver who learns the slack windows, not the one passing through for a single tank.

The bottom at Marroquí reads as layered time. The amphorae and millstones on the Levante wall, and the anchor stock on the Poniente sand, point to first-century Roman trade through the Strait, one of the choke points for any vessel between the western Mediterranean and the Atlantic. The headland takes its name from Tarif ibn Malik, who launched the Islamic conquest of Hispania from this coast in 711 AD. Isla de las Palomas was joined to the mainland by a causeway in 1808 and held a military installation from the 1930s until 2001, which is much of why the surrounding seabed escaped heavy use through the 20th century. The admiralty anchors at Poniente are most likely later naval debris and not individually dated. All of it is protected archaeology. You look and photograph; you do not touch anything.

Check the day's plan with the centre before you set out, because the tide tables write the schedule and the face can change on the morning. Marroquí is the dive centres lead with when conditions are right and the first they cancel when the wind or the slack is wrong. You cannot dive the island independently; every dive here runs through an authorised centre.

Dress warmer than southern Spain implies. The Atlantic flow holds bottom temperatures near 15 to 17 degrees through peak summer, so a 7mm and hood is the summer floor; a 5mm two-piece is widely reported as too thin, and a drysuit suits the cooler months. Carry an SMB for the drift potential on Levante, plus a compass and computer, and a torch for the Levante overhangs and the Dendrophyllia cave. The deeper lines, to the Roman artefacts near 40 metres or the Poniente sand floor at 45, are deep or technical territory with their own gas plan. If conditions only allow one dive, take it knowing the day can still get scrubbed. Tarifa has good days and less good days, and the divers who get one shot can leave with either.