Snorkelling

Intro to snorkellingTo swim underwater and experience marine

life first hand is a unique experience

You experience:Water pressureChanges in light intensityMarine topography (landscape) & marine life

Comparing Sea & LandOn land, cows eat grass and humans eat cows.

However in the sea, the grass is microscopic and is eaten by microscopic animals called zooplankton.

At the top of the food chain are the predators – humans are not on the top of the food chain!!!

On land humans have a massive impact and have altered the environment. When you snorkel under the sea, you quickly learn that the seascape is largely unaltered by humans

What will you learnHow to enter the water, float, duck dive,

clear your mask, equalising the pressure in your ears and be comfortable underwater

Best place to learn is in a swimming poolOnce the basics are competent then we will

venture out to the seaSnorkelling in a rock pool is a great way to

gain your confidence

EquipmentBasic equipment for snorkelling includes:

A maskSnorkelFinsWet suitStinger suit (tropical climates)BootiesWeight belt

EquipmentIn general, the choice of equipment is based on 3

things:

1. Comfort: Any piece of equipment must be properly fitted. Firm but comfortable without causing discomfort after long periods of time.

2. Financial status of the snorkeller: Look for quality when purchasing equipment. Cheap inferior equipment does not last long and may be a threat to safety.

3. Suitability: Different localities or activities may require specialised types of equipment. Eg cold climates need thicker wetsuit, lycra stinger suits for tropical climates.

MasksThese place a layer of air between the eyes

and the water, allowing clearer vision beneath the surface

Types of masks:Silicone masksOne lens masksSplit lens masksMasks with corrective lenses – allow people

who wear spectacles to see better underwaterTailored masks – preset focal length.

Safety, hygiene & comfortUse your own equipmentWhen not in use equipment should be stored away

from light and not with pool maintenance materials

Standards markingsLeaders should carry a knifeVests should conform with Aust. StandardsGoggles should never be worn – no way of

equalising pressure around the eyes or clearing water

Wash clean after useNever leave near heat source

SnorkelsShould have a smooth contoured “J” shape without

any sharp bends – this reduces drag & allows for smoother breathing

Mouthpiece should be comfortable fit& firmly attached to the tube

An average length of 30-40cm and diameter of 2cm is recommended

When selecting a snorkel, it should be attached to the mask straps on the left side of the head, placed in a position & checked for comfort (this can be done with a snorkel keeper or rubber band)

SafetyYounger children or people with small lung

capacities require a snorkel with a small bore.

Try to avoid snorkels with valve devices or table tennis balls on top. These can create dangerous situations as the ball may block the top of the snorkel on the surface cutting off air supply.

FinsThese propel the snorkeller through the

water and fall into 2 categories Open heeledFull booted

Open heeled finsRequire wet suit booties which are worn

inside open heeled fins

They should be light, naturally buoyant with a semi-rigid blade

Booties are particularly useful use when snorkelling in rocky or coral areas as you are able to walk to your snorkelling site

Full booted finsLess expensive and should be sized slightly

larger than shoe size to reduce cramps & incorporate the features of the open heel fin

Full booted fins come off quite easily & are very good when snorkelling entries are to be made from vessels at sea

Materials used in finsRubber and silicone Advantage of silicone – less likely to

deteriorate with time if washed in fresh water after use and stored in dry place

Rubber fins will deteriorate with time and last about 3-4 yrs.

All materials are subject to abrasion from rocks or coral and the more they come in contact with sharp substrata, the more they will wear.

Problems with finsDon’t fit properlyCramps and blisters occur if fins are too tightLose a fin if they are too big

Using booties can also overcome many problems but increases cost

A good fitting fin should feel like a good fitting shoe

HypothermiaHypothermia is caused when the body temp. drops to the point it

cannot recover

At sea, when the body is continually wet, this cooling extends to the blood vessels below the skin lowering the temp. of the blood

Continued cooling of the blood will affect the organs to which it flows and their normal functioning

Death occurs when core body temp drops below 26 degrees

To help marine divers charts are drawn of the life expectancy survival times at sea