A Zakynthos scuba diving trip takes divers under the clear Ionian Sea off Zakynthos, among caves, arches and seagrass. Beginners and certified divers dive with an instructor. It is one of the scuba diving trips in Greece on Greece VIP.
This post covers what a Zakynthos scuba diving trip includes, the dive sites and the Keri caves. It also covers sea life, the marine park rules and how beginners start. Depth, the Ionian Sea and safety follow. What to wear, the best season and common questions come last.
Each section ends with a Zakynthos scuba diving trip or sea tour that can be booked online.
What does a Zakynthos scuba diving trip include?
A Zakynthos scuba diving trip includes the full dive kit. It covers a buoyancy jacket, an air cylinder and lead weights on a belt. The regulator, which feeds air to the mouth, has a spare mouthpiece. Each piece keeps a diver safe.
The scuba in Zakynthos scuba diving is a word from 1952. Major Christian Lambertsen made it up. He served as a doctor in the U.S. Army Medical Corps from 1944 to 1946.
He first called his breathing set Laru, short for Lambertsen Amphibious Respiratory Unit. It was a closed-circuit rebreather, a set that cleans and reuses each breath. Like radar, scuba is now a normal word written in small letters.
Diver cards, proof of training, began in the year scuba got its name. A university ocean institute brought them in after two divers died using its equipment.
The open-circuit set on a Zakynthos scuba diving trip goes back to 1943. Two Frenchmen, Émile Gagnan and Jacques-Yves Cousteau, invented it. Open circuit means each used breath leaves the set as bubbles.
Early scuba divers swam with no buoyancy aid at all. In an emergency, they had to drop their weights. In the 1960s came adjustable life jackets worn round the neck, nicknamed horse collars.
A Zakynthos scuba diving trip now uses a buoyancy compensator, a jacket that holds air. It also goes by BCD, stabilizer, stab jacket or wing. The air inside shrinks on the way down and swells on the way up. This follows Boyle’s law of gas and pressure.
The common inside volume of a scuba cylinder runs from 3 to 18 litres. Bar is a unit of pressure, and 232 bar is a popular working pressure. A 300 bar cylinder cannot use a yoke clamp. It takes the other common fitting, the DIN valve.
- Cylinders: The tanks on a Zakynthos scuba diving trip are made of aluminium or steel alloys.
- Octopus: This spare second stage, or extra mouthpiece, sits on the diver’s own regulator.
- Pony bottle: This small separate cylinder carries its own complete regulator.
- Weights: Lead is used because it is dense, cheap, easy to cast and slow to corrode.
Weight belts on a Zakynthos scuba diving trip close with a quick-release buckle. The buckle lets a diver dump the weight fast in an emergency.
Where are the dive sites on Zakynthos?
Zakynthos scuba diving takes place along the south and west coasts. Agios Sostis and Marathonisi are two islets in the community of Lithakia. Cape Marathia, the southern tip, has a reef dive of its own. The west coast adds beaches with sea caves.
Until the earthquakes of 1633, it was joined to the Agios Sostis cape at Lithakia. Its name comes from a church of Agios Sostis that stood on it in the 16th century.
The rocky ground of Agios Sostis once supplied building stone. The islet also holds small coves and a pine wood. Marathonisi, the second islet, covers 280 stremmata, a Greek unit of land.
On Marathonisi, thick scrub reaches 3 metres high in places and is hard to walk through. Its one sandy beach runs 150 metres along the northern tip. The other shores are rocky and steep. The islet has been private property since the 13th century.
Laganas beach is about 7 km of fine sand facing a shallow, clear sea. Kalamaki lies about 3 km northeast of Laganas, and its south coast beach stretches 3,430 metres. Between Zakynthos scuba diving days, turtle boat tours on Zakynthos run along the same coast.
The west coast beaches for Zakynthos scuba diving are Limnionas and Roxa. Both belong to the community of Agios Leon. They are known for bold jumps into the sea. Each lies about 4 km from the mountain village of Agios Leon.
Cape Marathia lies 42 km across the sea from Cape Katakolo in the Peloponnese, on the Greek mainland. Its Zakynthos scuba diving reef is called Elefantas, which means Elephant.
- Paths: The marine park has worked on underwater paths for Zakynthos scuba diving and snorkelling.
- Park zones: On land, the park has seven core zones and three habitat protection zones.
- Park size: Its land area covers 14.2 square kilometres, with a buffer zone of 31.2 square kilometres.
In 1986, the Greek parliament protected the Kalamaki area by law. Night visits to the beach were banned at the same time. Zakynthos scuba diving on the south coast takes place beside shores with strict rules like this one.
What does a Zakynthos scuba diving trip see at the Keri caves?
A Zakynthos scuba diving trip at the Keri caves visits Petalouda, a sea cave named after the butterfly. This dive site sits at Cape Marathia, close to Cape Keri. Nearby, the Keri lighthouse looks out on two huge white rocks, the Big and Small Mizithra.
Cape Marathia is named after Marathias, a small coastal settlement to its northeast. Cape Keri takes its name from the village of Keri. Just north of Cape Marathia, Skopos hill rises to 413 metres.
Keri village stands at 200 metres among olive groves, vineyards and woods of pine and kermes oak. Keri is the first village of a mountain line that runs from the south to Skinari. Skinari is the island’s far tip.
The stone Keri lighthouse stands 1 km southwest of the village. The light was relit in 1954, running on oil. In 1982, it ran on electricity for the first time. Divers on a Zakynthos scuba diving trip see it from the sea.
Seen from the Keri lighthouse, the sea turns green-blue over rock and silver over sand. For a Zakynthos scuba diving trip, that colour marks where rock gives way to sand.
In the early 1980s, small tar-filled amphorae came up from the sea at Keri port. The clay jars had pointed bottoms. They prove an ancient trade in tar.
Deep under a Zakynthos scuba diving trip, huge blocks of the earth’s crust meet. The Ionian Islands basin is part of one block, the Preapulian Zone. Another block, the Ionian Zone, is pushed westward over it.
The Paxi Zone of the Ionian islands holds marl and gypsum. Marl is a limy mud rock, and gypsum is a soft mineral. Both date from the Cretaceous to the Miocene, two ages of the earth’s past.
- Signal: For Zakynthos scuba diving boats at Keri, the light gives one white flash every 10 seconds.
- Colours: The lighthouse is painted white, with a green lantern roof.
- Old port: In ancient times, the port of Keri was known as Nafthi.
Sea stacks are tall rock pillars left standing in the sea. They form best in flat rock layers, above all on limestone and chalk cliffs. Coasts like that give a Zakynthos scuba diving trip walls and gaps to explore.
Which sea life does a Zakynthos scuba diving trip meet?
A Zakynthos scuba diving trip meets groupers, morays and pillow coral in the marine park. Bath sponges, red starfish and fan worms live on the seabed. Pen shells hide in seagrass meadows. Monk seals and loggerhead turtles pass through the same water.
In the marine park, the zone below the low tide line ends at the deepest Posidonia meadows. Posidonia is a sea grass that forms thick underwater lawns. Those meadows stop at about 40 m, and Zakynthos scuba diving trips swim over them.
On a Zakynthos scuba diving trip, groupers stand out as top hunters of the Mediterranean Sea. They feed on crabs, octopuses and fish. Young groupers stay near the coast and look green. Larger ones turn brown with yellow spots and move into deeper water.
A grouper can weigh more than 30 kg. Marine protected areas seem to help grouper numbers recover. In the Mediterranean, dusky groupers spawn, or release their eggs, from June to September. They gather in small clusters, with about seven females to each male.
Zakynthos scuba diving trips also meet the Mediterranean moray, a long eel with no side fins. Morays hunt fish, crabs and cephalopods, the octopus family, and they also eat dead animals. A moray bite is dangerous mainly because of the mildly toxic slime on its skin.
The park calls pillow coral the only reef-building coral of the Mediterranean that grows in colonies. Those colonies give shelter to small animals without backbones. A colony reaches up to 50 cm across. It is built from maroon polyps, tiny soft animals about 5 mm wide.
Bath sponges grow on rocks, sand and steep walls across the Mediterranean. They reach down to 100 metres deep. The noble pen shell, a tall fan-shaped clam, lives in sand and Posidonia meadows. It can live for 20 years.
- Red starfish: It moves and breathes through a system of water channels inside its body.
- Fan worm: This tube worm pulls its colourful crown of tentacles inside when danger comes close.
- Monk seals: Fewer than 15 Mediterranean monk seals live in the marine park area.
- Loggerheads: Park research called Caretta Odyssey showed Zakynthos turtles spread out to feeding areas across the Mediterranean.
Six alien fish species swim in the park’s waters. They share it with 4 alien plants and 3 alien animals without backbones. Alien species are newcomers from other seas. Zakynthos scuba diving brings both old residents and these newcomers into view.
What rules protect the sea on a Zakynthos scuba diving trip?
A Zakynthos scuba diving trip takes place inside a protected national marine park. Marked sea zones and patrol boats keep watch over the water. Divers must leave every sea creature where it lives. Even air bubbles inside sea caves count as a risk to wildlife.
Zakynthos scuba diving follows rules from a Presidential Decree, an order from the head of state. The decree created the marine park and set its rules. It appeared in Government Gazette 906D, the official state record, on 22 December 1999.
The park was the first national park in Greece run by its own Management Agency. The IUCN, a world body for nature protection, lists it in protected area category II. It takes in three Natura 2000 areas, which are sites on the EU nature network.
The protected area covers Laganas Bay, the islets of Marathonisi and Pelouzo and the Strofadia islands. Park rules list Zakynthos scuba diving as one way to discover this sea. Boat trips, swimming and canoeing share the same list.
Law 4685/2020 created NECCA, the Natural Environment and Climate Change Agency. NECCA merged 36 park bodies into 24 management units. It took over the park’s Management Body by a ministerial decision in Government Gazette 800/B. That decision came out on 23 February 2022.
Today a NECCA unit for Zakynthos and Ainos National Parks runs the park. It has branch offices in Kerkyra and Argostoli. Buoys mark the sea zones used by Zakynthos scuba diving trips. Park staff and the Coast Guard patrol them by boat.
- Take nothing: Visitors must not take sea urchins, starfish or other sea creatures out of the water.
- Cave care: Divers’ bubbles can harm animals fixed to cave ceilings, so the park wants regular cave checks.
- Turtle zone: Zones B and C hold a special area for gentle turtle watching.
- Beach hours: Turtle nesting beaches open to visitors only between early morning and sunset.
On land, the clay pillars of Gerakas beach, called Glines, are a protected rock landmark. Taking or using the clay is forbidden. The same care for shore and sea protects Zakynthos scuba diving for future visitors.
How do beginners start a Zakynthos scuba diving trip?
A Zakynthos scuba diving trip for beginners starts with a try dive under an instructor’s close watch. Breathing through the mouthpiece comes first. Then ear clearing and simple hand signals follow. A medical form checks that each diver is fit.
A try dive also goes by the names introductory scuba experience, trial dive or resort dive. It gives no diving licence, or certification. It simply lets a beginner test Zakynthos scuba diving with an instructor close by.
The regulator is the mouthpiece that feeds air from the tank. On a Zakynthos scuba diving trip, beginners first practise breathing from it at the surface. At shallow depth, they learn to take it out, put it back and clear the water out.
Before Zakynthos scuba diving, each beginner needs to swim at least 25 m without a float. The CMAS introductory scuba experience sets a minimum age of 14. It goes no deeper than 10 m in open water.
Beginners who enjoy Zakynthos scuba diving can then train as a Supervised Diver. This level follows the world standard ISO 24801-1. It allows diving only under the direct watch of a dive professional.
Health comes first on any Zakynthos scuba diving trip. The RSTC medical declaration form and its notes for doctors were revised after a three-year review. Diving medicine experts carried out that review. That form is a health checklist for new divers.
The Valsalva manoeuvre is the first ear-clearing trick taught. The diver pinches the nose, closes the mouth and gently tries to breathe out through the nose. Swallowing or yawning also helps open the Eustachian tubes, the air pipes from the ears to the throat.
- OK: A circle made with the thumb and forefinger means all is well.
- No air: A flat hand drawn across the throat means the diver is out of air.
- Ear trouble: Pointing a forefinger at the ear means that ear will not clear.
- Surface OK: Arms form a big circle overhead, or a hand taps the top of the head.
Pinching the nose while swallowing is called the Toynbee manoeuvre. A blocked Eustachian tube, as during a common cold, rules out Zakynthos scuba diving. Trapped air can burst the eardrum on the way up.
How deep can a Zakynthos scuba diving trip go?
A Zakynthos scuba diving trip relies on recreational depth limits set by training bodies. The European Autonomous Diver standard stops at 20 m. Deeper water changes gas use, buoyancy, body heat and clear thinking. Every metre of depth gets careful planning.
On a Zakynthos scuba diving trip, water presses harder with each metre of depth. Open-circuit scuba lets each breath out as bubbles. There, gas use rises with that pressure. It also depends on how much air a diver breathes each minute.
Buoyancy, the force that makes a diver float or sink, changes fastest near the surface. In shallow water, each metre changes the total pressure by the biggest share. So the last metres of a Zakynthos scuba diving ascent need careful control.
Deeper Zakynthos scuba diving brings the risk of nitrogen narcosis. It is a change in the mind caused by breathing gas at high pressure. It feels like being drunk. A climb to shallower water clears it within minutes, with no long-term effects.
Divers also call narcosis the “raptures of the deep” or the “Martini effect”. The word comes from the Greek narkosis, “the act of making numb”. Homer and Hippocrates used its root, narke, for numbness.
Air brings a second limit on a Zakynthos scuba diving trip. Below 56 m on air, oxygen pressure passes 1.4 bar. That is the common limit for recreational dives. Past that point, oxygen poisoning becomes a growing danger.
The no-stop limit is the time a diver can spend at one depth. Within that time, the diver can surface without decompression stops. These stops are pauses on the way up that let gas leave the body.
- Deep dive: PADI counts any dive from 18 to 30 m as a deep dive in recreational diving.
- Council limit: The Recreational Scuba Training Council sets a depth limit of 40 m for divers.
- Mixed gas: The deepest scuba dive reached 332 m in Dahab, Egypt, on trimix, a special gas blend.
No Zakynthos scuba diving trip goes near the open-sea record. That record, 534 m, was set in the Mediterranean Sea in 1988. French Navy divers took part in the Hydra 8 programme behind it.
What does the Ionian Sea add to a Zakynthos scuba diving trip?
A Zakynthos scuba diving trip takes place in the Ionian Sea. This basin covers about 169,000 km2. A deep trench, shifting currents and salty water shape this sea. Its deepest hole also goes by the names Oinousses Deep and Vavilov Deep.
The sea around a Zakynthos scuba diving trip has fixed borders. The International Hydrographic Organization, a body for sea charts, sets the southern edge. It draws a line from Cape Matapan to Cape Passero, the southern tip of Sicily.
Below the Ionian Sea runs the Hellenic Trench, a long, deep groove in the seabed. Its main leg, from Kefalonia to Crete, is about 600 km long. One estimate traces a wider arc of 1,200 km, from offshore Zakynthos to offshore Rhodes.
A Zakynthos scuba diving trip starts from an island with its own undersea ridge. The Zakynthos-Strofades Ridge joins the island to the small Strofades islands to its south.
Deep below, the African plate slides under the Ionian Islands, a process called subduction. It began in the Pliocene, about 4 million years ago. The plates move at about 35 mm per year.
The North Ionian Gyre is a large rotating current. When it turns one way, its water comes from the Adriatic. When it turns the other way, its water comes from the Levantine Sea.
The deep Ionian floor also serves science. In March 2003, the prototype of the NESTOR neutrino telescope went down to 3800 meters. It sat about 30 kilometers off the Greek coast near Pylos. Such a telescope is built to catch neutrinos, which are tiny particles.
- Salt: At 5 m deep, the wider basin averages 38 PSU, a unit of saltiness.
- Plankton: Growth stays very low from June to October, as warm top water stays cut off.
- Sea mammals: ACCOBAMS lists the trench as an International Marine Mammal Area because ships can hit whales there.
A Zakynthos scuba diving trip explores only the top metres of the Ionian Sea. Below that layer lie moving plates, a deep trench and currents that change direction.
How safe is a Zakynthos scuba diving trip?
A Zakynthos scuba diving trip relies on clear rules and good habits for safety. Divers rise slowly, stay close to a dive buddy and follow their own dive computer. Flags and marker buoys warn passing boats that divers are underwater nearby.
A Zakynthos scuba diving trip ends with a slow rise to the surface. For dives deeper than 6 m, the top rising speed is about 10 m per minute. A dive computer warns the diver and adds extra stop time after a faster climb.
A dive computer is a small device that tracks depth and time underwater. Good practice on a Zakynthos scuba diving trip is one computer per diver, never shared. As a rule, a switch to another computer waits more than 24 hours.
Flying after a Zakynthos scuba diving trip has its own rules. A drive up high mountains after diving counts as a flight to that height. In the normal case, pool lessons at limited depth need no wait before a flight.
Buddy diving pairs divers so each one watches out for the other. A group of more than three divers is no longer a buddy system. If buddies lose each other, they search for one minute. Then each one starts the climb to the surface.
Boats near a Zakynthos scuba diving site need to know where divers are. The diver down flag is red with a white diagonal stripe. Navy veteran Denzel James “Doc” Dockery of Michigan created it.
A delayed surface marker buoy is a float sent up near the end of a dive. It tells the surface that divers are rising. It also shows where they will come up.
- Small boats: A dive boat too small for Rule 27 collision signals must fly a rigid Alpha flag.
- Marker buoys: Buoys mark drift dives, night dives, misty days and seas of Beaufort force 2 or more.
- First dive computer: Italians De Sanctis and Alinari designed a mechanical “decompression meter” in 1959.
Rules and good habits keep a Zakynthos scuba diving trip calm and well run. Slow climbs, close buddies and clear signals share a single goal. Every diver gets back on board.
What do divers wear on a Zakynthos scuba diving trip?
A Zakynthos scuba diving trip calls for a neoprene wetsuit, a mask and a pair of wide fins. Neoprene boots, gloves and a hood add extra warmth in cooler water. Each item works best when it fits closely without pinching.
A Zakynthos scuba diving wetsuit is made of neoprene. This synthetic rubber foam is closed-cell, which means it holds tiny sealed bubbles of nitrogen gas. The gas trapped in the foam keeps the diver warm, not the water inside the suit.
On a Zakynthos scuba diving descent, the suit foam gets squeezed. Neoprene loses about 30% of its volume in the first 10 m. It loses another 30% by about 60 m. Its lift in the water drops by the same share.
Foam also makes a diver float. A full one-piece suit of 6 mm holds roughly 10 liters of foam. It needs about 6 kg of extra weight to reach neutral buoyancy. That is the point where a diver neither sinks nor rises.
On a Zakynthos scuba diving trip, fit matters as much as thickness. A suit that is too tight makes breathing hard. A loose suit lets cold water flush through it.
Semi-dry suits add tighter seals at the wrists, neck and ankles. A watertight zip is the usual extra. These suits fit water between 10 and 20 °C. The thickest common type is an 8 mm semi-dry suit. It covers the torso, arms and legs.
A well-fitting hood helps even in fairly mild water. The head and neck lose heat in step with how much skin is bare. A hood also guards against surfer’s ear, a bone growth in the ear canal.
A Zakynthos scuba diving mask has a tempered glass faceplate. Its skirt of silicone or rubber seals against the face. The mask must enclose the nose. Divers breathe out into it on the way down. That stops mask squeeze, a suction that pulls the mask hard onto the face.
- Boots: Standard boots use 5–6 mm of neoprene, with a tough rubber sole that grips pebbles.
- Gloves: Thicker neoprene gloves make fingers clumsy and less able to feel.
- Fins: Stiff paddle fins allow back kicks that do not stir up sand from the seabed.
- Fin straps: Thick boots squeeze at depth, so a fin strap needs extra stretch to stay on.
Every piece of Zakynthos scuba diving kit plays its part. Warm neoprene, a sealed mask and strong fins work as one set. Together they keep a diver warm, balanced and comfortable underwater.
When is the best season for a Zakynthos scuba diving trip?
A Zakynthos scuba diving trip finds the warmest sea from late June into summer. Late spring brings cooler water and the female loggerhead turtles of Laganas Bay. Autumn keeps mild air, but strong storms can form over the Ionian Sea.
Sea temperature shapes a Zakynthos scuba diving trip. In the month before June, the water sits at 17–22 °C. It only climbs to 26–28 °C in late June. Cooler water calls for a thicker wetsuit.
Female loggerhead turtles visit Laganas Bay from late April to early August. Loggerheads are large sea turtles. Tracking shows they leave the warm shallows for deeper water once the open sea passes 26 °C.
Sea surface temperature at Zakynthos rose over three decades, from 1982 to 2012. Across those years, the sea off Crete averaged 0.4 °C warmer. It was compared with the sea at Zakynthos and Kyparissia.
Zakynthos scuba diving days also come with mild air on land. Average lows reach 18.2 °C in June and 20.4 °C in July. October still keeps an average daily high of 23.0 °C, with nights at 15.7 °C.
Summer heat can be strong. Record highs reach 39.4 °C in June and 40.0 °C in August. Humidity, the amount of water in the air, averages 61.2% in August.
Clear water matters on a Zakynthos scuba diving trip. Underwater visibility drops with floating particles and dissolved organic matter. Layers that differ in saltiness, called haloclines, also reduce it. So do layers that differ in temperature, called thermoclines.
The Mediterranean is among the poorest ocean regions in the world for nutrients. Its chlorophyll levels, a sign of tiny floating plants, are very low. In other places, particles and dissolved matter turn coastal waters green.
- Visibility test: The proposed standard measures how far away a black target stays visible sideways.
- Storm zone: The Ionian Sea is one of two main birthplaces of hurricane-like storms in the Mediterranean.
- Medicane Ianos: This storm brought gusts of 195 km/h to Zakynthos on 17 and 18 September 2020.
- Rain days: The island records 78.5 days a year with 1.0 mm of rain or more.
Each Zakynthos scuba diving season has its own mix of water warmth, wildlife and weather. Rest days between dives also leave time for boat trips to the Blue Caves.
What do travelers ask about a Zakynthos scuba diving trip?
A Zakynthos scuba diving trip raises practical questions before the first dive. Travelers ask how to reach the island by air or by sea. Others ask about contact lenses, seasickness and underwater cameras. Each topic shapes how ready a diver feels on the boat.
How do divers fly in for a Zakynthos scuba diving trip?
Flights for a Zakynthos scuba diving trip land at Dionysios Solomos airport, code ZTH. It lies 4.3 km from Zakynthos town and opened in 1972. Night flights are restricted, because loggerhead turtles lay eggs on marine park beaches beside the airport.
Is there a ferry route for a Zakynthos scuba diving trip?
Yes. Ferries to Zakynthos leave from Kyllini, a port town in Elis on the Ionian coast of the mainland. Kyllini lies 28 km northeast of Zakynthos city. Its ferries also serve Kefalonia, and the ruins of the medieval town of Glarentza lie there.
Can contact lens wearers join a Zakynthos scuba diving trip?
Yes, contact lenses can be worn under a dive mask. A lens can be lost if the mask is knocked off in rough water. Masks also take prescription lenses, bifocals included. Water is not advised for cleaning lenses. Poorly chlorinated tap water can taint them with Acanthamoeba, a tiny organism.
What helps with seasickness on a Zakynthos scuba diving trip?
Seasickness medicine works best when taken before symptoms start. Divers on a Zakynthos scuba diving trip need to weigh a drug’s risks against its benefits. Scopolamine, one such medicine, can blur vision. The anti-nausea drugs ondansetron and metoclopramide do not work against motion sickness.
Can divers take photos on a Zakynthos scuba diving trip?
Yes. Camera housings stay watertight thanks to silicone O-rings, which are soft sealing rings. A flash can light up particles in front of the lens as bright dots, called backscatter. Photographers place the flash away from the line of the lens.
Featured photo: Zakynthos small-group scuba diving for beginners, via GetYourGuide.