A Rhodes snorkeling tour means swimming at the surface of the sea around Rhodes, the largest island of the Dodecanese. It is one of the Greece tours on this site. The notes below look at the trip through its gear and its sea life: snorkeling, the diving mask, swim fins, the wetsuit, the cuttlefish and freediving, then four sea terms. Each term is explained in plain words, and the facts come from reference articles.
What does a Rhodes snorkeling tour mean?
A Rhodes snorkeling tour means a trip to swim at the sea surface around Rhodes, a Dodecanese island. Snorkeling is a popular recreational activity, particularly at tropical resort locations. Recreational means done for fun, not for work. Dodecanese is a chain of Aegean islands.
A snorkel barrel is made of a rigid material such as plastic, light metal or hard rubber. The mouthpiece helps to keep the snorkel in the mouth. The mouthpiece is made of soft, flexible material, first natural rubber and later silicone or PVC. A barrel is the main tube of a snorkel.
By creating an airspace, the mask enables the snorkeler to see clearly underwater. Swimfins for more efficient propulsion are common. Short, stiff-bladed fins are effective for short bursts of acceleration and maneuvering. A wetsuit is also worn in cooler waters. Propulsion means the force that pushes a swimmer forward on any Rhodes snorkeling tour.
Being non-competitive, snorkeling is considered more a leisure activity than a sport. Underwater photographs of natural subjects become database records of species observations. Shallow reefs ranging from 1 to 4 meters are favored by snorkelers. A Rhodes snorkeling tour fits this leisure picture of the activity.
- Snorkel: A snorkel is a tube that lets a swimmer breathe with the face in the water.
- Reef: A reef is a raised band of rock or coral just below the sea surface.
- Leisure: Leisure means free time spent on things a person enjoys.
A Rhodes snorkeling tour therefore rests on a short list of simple tools. The next sections cover the mask, fins, wetsuit, cuttlefish and freediving in plain words. Each term gets a plain definition at first use. Only reference facts are used. Plain words come first.
On a Rhodes snorkeling tour, what does the diving mask add?
A Rhodes snorkeling tour meets the diving mask, a window with an air space. Underwater the eye cannot focus light on the retina because water bends it at a different angle. An air space in front of the eyes lets the eye focus nearly normally.
A diving mask can have one tempered glass faceplate or two lenses in front of the eyes. Early diving masks were made with a single pane of glass or transparent plastic. A retina is the layer at the back of the eye that senses light. Tempered glass is glass treated to make it stronger.
The scuba mask’s flat window separates the eyes from the surrounding water by a layer of air. By wearing a flat diving mask, humans can see clearly under water. Nine national and international standards relating to diving masks are known to exist. A standard is an agreed rule for how a product is made.
Diving masks can be fitted with prescription lenses for divers who need optical correction. Bifocal lenses are also available for this application. If one medium has a particular curved shape, it functions as a lens. For a Rhodes snorkeling tour, the mask is a simple window with a long history.
- Prescription: A prescription lens is a lens made to correct a person’s sight.
- Bifocal: A bifocal lens has two parts that focus at different distances.
- Lens: A lens is a curved piece of glass or plastic that bends light.
A Rhodes snorkeling tour therefore meets the mask as a window with a layer of air. Its glass, its lenses and its rules are plain facts for any Rhodes snorkeling tour. Swim fins come next. All terms have plain definitions.
On a Rhodes snorkeling tour, what do swim fins bring?
A Rhodes snorkeling tour meets swim fins, finlike accessories worn on the feet, legs or hands. A swimfin has a blade for propulsion and a means of attaching it to the foot. A blade is the flat part of a fin. A fin extends the foot.
Swim fins are made from rubber, plastic, carbon fiber or combinations of them. Full-foot fins slip on like a shoe, over bare feet or neoprene socks. Open-heel fins are held to the foot by springs or straps. Neoprene is a soft synthetic rubber that a Rhodes snorkeling tour topic meets in wetsuits.
Paddle fins have simple plastic, composite or rubber blades that extend the feet while kicking. Freediving fins are far longer than paddle fins and suit slow, stiff-legged kicks. Composite freediving blades are more resilient and absorb less energy when flexing. A composite blade is made of more than one material. Resilient means springy.
Louis de Corlieu, a Frenchman and naval officer, invented the modern swimfin. In April 1933 Corlieu registered a patent for two foot fins and two spoon-shaped hand fins. A monofin is a single fin blade attached to foot pockets for both feet. A patent is a legal right that protects an invention.
- Bifins: Two separate fins, one for each foot, are also called bifins, to tell them from monofins.
- Efficiency: Free divers favour extremely long fins for efficiency of energy use.
- Foot pocket: A foot pocket is the shaped part of a fin that holds the foot.
A Rhodes snorkeling tour therefore meets swim fins as a simple tool with a clear history. Their blades, pockets and materials are plain facts for a Rhodes snorkeling tour. The wetsuit comes next. Every claim comes from a reference article.
On a Rhodes snorkeling tour, what does the wetsuit add?
A Rhodes snorkeling tour meets the wetsuit, a garment worn to provide thermal protection while wet. Wetsuits are made of closed-cell foam neoprene, which is a synthetic rubber. The insulation of neoprene foam depends on gas bubbles enclosed within the material.
Physicist Hugh Bradner invented the modern wetsuit in 1952. Thin sheets of tougher material, such as nylon or later spandex, were added to the foamed neoprene. Thickness ranges from 2 mm or less for a shortie to 8 mm for a semi-dry suit. A shortie is a suit with short legs and arms.
A 5/3 wetsuit has a 5 mm torso thickness and a 3 mm limb thickness. In still water the body loses heat 20 to 25 times faster than in still air. Wetsuits can give adequate protection in warm to moderately cold waters. A torso is the body without its arms and legs.
The suit type depends on the water temperature and the depth of the planned dive. For a Rhodes snorkeling tour, the wetsuit is one more tool in the story of the sea. Closed-cell means that the bubbles in the foam are sealed apart from one another. Thermal means linked to heat.
- Nylon: Nylon is a strong thread made from chemicals in a factory.
- Spandex: Spandex is a stretchy synthetic fibre that returns to its shape.
- Physicist: A physicist is a scientist who studies matter, energy and motion.
A Rhodes snorkeling tour therefore meets the wetsuit as a garment that holds gas bubbles for warmth. Its foam, thickness and history are plain facts for any Rhodes snorkeling tour. An animal, the cuttlefish, comes next. All terms stay plain.
On a Rhodes snorkeling tour, what does the cuttlefish bring?
A Rhodes snorkeling tour meets the cuttlefish, a marine mollusc in the family Sepiidae. Cuttlefish range from 15 to 25 cm in size. A cuttlefish is not a fish. The largest species, the giant cuttlefish, reaches 50 cm in mantle length. A mollusc is a soft-bodied animal.
The cuttlebone is porous and made of aragonite. The cuttlefish adjusts buoyancy by changing the gas-to-liquid ratio in its cuttlebone. Porous means full of tiny holes. Aragonite is a mineral form of calcium carbonate. A Rhodes snorkeling tour topic like this one starts with the body of the animal.
A cuttlefish pupil has a smoothly curving W shape. Cuttlefish cannot see color but can perceive the polarization of light. Cuttlefish can change their skin color within one second. A pupil is the dark opening in the eye. Colour change is a skill of the skin. Polarization is the direction in which light waves vibrate.
Cuttlefish are present along the coasts of East and South Asia and Western Europe. Cuttlefish are totally absent from the Americas. Cuttlefish eat small molluscs, crabs, shrimp, fish, octopuses and other cuttlefish. Absent means not found there. A coast is the strip of land next to the sea. Present means found there.
- Mantle: Mantle names the main body of a cuttlefish, behind its head.
- Cuttlebone: The cuttlebone is the light inner shell that lies inside the body.
- Mollusc: The molluscs include snails, clams, squid and octopuses, as well as cuttlefish.
A Rhodes snorkeling tour therefore meets the cuttlefish as a mollusc with an inner bone. Its size, its eyes and its range are plain facts for a Rhodes snorkeling tour. A sport, freediving, comes next. Plain words explain every term.
On a Rhodes snorkeling tour, what does freediving add?
A Rhodes snorkeling tour meets freediving, diving that relies on breath-holding, not on breathing apparatus. Apparatus means the equipment used. Historically, the term skin diving was used interchangeably with freediving. Breath-holding means keeping air in the lungs. Resurfacing means coming back up to the surface.
Freediving is a distinct discipline focused on maximizing breath-hold time, depth or distance. Freediving activities include spearfishing, underwater photography, synchronised swimming and underwater hockey. Breath-holding ability depends on on-board oxygen stores, metabolic rate reduction and hypoxia tolerance. A discipline is a set kind of event with its own rules.
In ancient times, freediving was the only option, apart from reeds and leather bladders used now and then. In 1940, Dottie Frazier pioneered freediving for women in the United States. Ama divers in Japan began collecting pearls about 2,000 years ago. So freediving gives a Rhodes snorkeling tour topic a long past.
Competitive freediving is currently governed by two world associations. Skandalopetra diving competitions are freediving’s only truly team event, with two athletes per team. Eleven recognised disciplines are defined by the two associations, and a dozen more are practised locally. A dozen means twelve. An association is a group that sets rules for a sport.
- Hypoxia: Hypoxia means a low level of oxygen in the body.
- Metabolic rate: Metabolic rate is how fast the body uses energy.
- Spearfishing: Spearfishing means hunting fish underwater with a hand-held spear.
A Rhodes snorkeling tour therefore meets freediving as a breath-hold sport with ancient roots. Its events, records and rules are plain facts for a Rhodes snorkeling tour. Four questions about the sea come last. Reference facts back every line.
Which questions matter before a Rhodes snorkeling tour starts?
A Rhodes snorkeling tour touches four sea terms: underwater vision, buoyancy, the sea cucumber and the grouper. Four short answers follow, one for each term. Each draws on a reference article. A term is a word that names one idea.
On a Rhodes snorkeling tour, what changes the way the underwater view looks?
Effects on underwater sight vary with the wavelength of light and the colour and turbidity of the water. Both relative and absolute depth perception are reduced underwater. Colour absorption is also affected by turbidity of the water and dissolved material. Turbidity means how cloudy the water is.
Which force keeps a body afloat behind a Rhodes snorkeling tour?
A pressure difference in the liquid results in a net upward force on the object. If the object is less dense, buoyancy can keep the object afloat. An object whose weight exceeds its buoyancy tends to sink. Buoyancy is that upward force. Dense means heavy for its size.
Which sea animal looks like a cucumber behind a Rhodes snorkeling tour?
Sea cucumbers are echinoderms from the class Holothuroidea. The body ranges from almost spherical to worm-like and lacks arms. The mouth is surrounded by tentacles, which can be pulled back inside the animal. An echinoderm is a sea animal such as a starfish. A tentacle is a long soft limb.
Which large sea fish swallows its prey behind a Rhodes snorkeling tour?
Groupers are marine ray-finned fish in the family Epinephelidae. Groupers can be over a meter in length. Groupers swallow prey rather than biting pieces off of them. Ray-finned means that the fins are held up by thin bony rays. A family groups animal kinds that share close ancestry.