General Guidelines are as follows, but keep in mind that it depends on specific watches recommendations. Check your Omega watch manual before using your Omega Watch. Hope these can help!

Water Resistance
From our experience, we would not recommend to swim with a Omega watch that has a water resistance of less than 100 meters or 10 bars/atm's. A Omega watch rated as Water Resistant may come in contact with water to a predetermined extent. Most watches have a measurement until which the depth of immersion is safe. It is important to remember that a water-resistant rating is based upon optimum conditions in a laboratory. Real life experience & aging of the gaskets will effectively decrease the manufacturer's specifications of water resistance over time. When water comes in contact with the movement, it is the worst scenario that can happen to a watch - thus we strongly suggest that you always work well within the parameters of the manufacturer's recommendations and have your Omega watch tested at least once a year.

Every Omega watch will remain water resistant provided that the crown, pushers, crystal, case and gaskets re main intact. We recommend you have the water resistance checked once a year by a service centre or agent, if possible before the bathing season.

1.Watches water resistant to 30m, 50m and 100m are protected against.
2.Watches water resistant to 120m and 1 5 0m can be used for deep-sea diving and are protected against.
3.Watches water resistant to 200m, 300m and 600m, with unidirectional turning bezel, can be used for deep-sea diving and are protected against. 

Precautions
Screw-in Crown If present, the screw-in crown should be fully secured at all times to provide additional protection against moisture and also to prevent air and dust from entering the watch to dry the oil inside. Water resistance cannot be guaranteed if the crown is not screwed in.
Plated Areas Perfume, synthetic materials, and rough treatment can accelerate the wear-off of gold plated areas.

Leather Salt water, perfumes and direct sunlight can accelerate the deterioration of leather straps. Clean water and a leather conditioner can prolong the life of a leather strap.

Other Considerations Avoid dropping the Omega watch, sudden shocks, chemical products, temperature extremes, and strong magnetic forces which can affect the watches appearance, value and function.

Watch Battery
If you are looking for a Omega watch you can rely on for accuracy, we would recommend a quartz Omega watch. You never have to worry about winding it or wearing it in order for it to work. In Quartz watches, a specially designed battery activates a Quartz crystal inside the movement that vibrates approximately 33 times per second. These vibrations translate into impulses by a computer chip that drives an electronic motor, which moves the watch's hands.

Generally an Omega battery lasts between 2-5 years but it depends on the watch, because some watches eat the batteries faster them others. We recommend that you take your watch to an authorized dealer to have the battery replaced. We do not recommend that you replace the battery at a local jeweler, since most manufacturers have a policy not to work on your Omega watch if it has been worked on by anyone who is not an authorized dealer.

Other Usage Recommendations
Magnetic fields: avoid placing your Omega watch on speakers or refrigerators, since these have strong magnetic fields.
Bathing in the sea: always rinse your watch with warm water afterwards.
Shocks: whether thermal or other, avoid them.
Crown: screw it in carefully to ensure that no water enters the mechanism.
Cleaning: for metal bracelets and for all water-resistant cases use a toothbrush with soapy water and a soft cloth for drying.
Chemical products: avoid direct contact with solvents, detergents, perfumes, cosmetic products etc., since they may damage the bracelet, the case or the gaskets.
Temperatures: avoid extreme temperatures above 60°C or 140°F below 0°C or 32°F or extreme temperature changes.
Chronograph push-pieces: Do not operate chronograph pushers under water in order to prevent water entering the mechanism.