The sea is a safe place. I always liken the sea to a highway. If you have never been on a highway before it is always wise to travel with someone who has been. Same with the sea. Never go swimming in water you are not familiar with alone. Always go with an experienced person.
If you cannot swim you should never go into water reaching above your knee. Water only one foot high with a strong enough current can move a car much less a person.
When a wave reaches a beach or coastline, it releases a burst of energy that generates a current, which runs parallel to the shoreline. This type of current is called a “longshore current.”
When wind and waves push water toward the shore, that water is often forced sideways by the oncoming waves. This water streams along the shoreline until it finds an exit back to the sea or open lake water. The resulting rip current is usually narrow and located in a trench between sandbars, under piers or along jetties.
A common misconception is that ordinary undertow or even rip currents are strong enough to pull someone under the surface of the water; in reality the current is strongest at the surface. This strong surface flow tends to damp incoming waves, leading to the illusion of a particularly calm part of the sea, which may possibly lure some swimmers into the area.
Most of the time people get caught in longshore currents or rip tides, they drown because they panic. They panic because they realise that they cannot reach the shore they just left and continue to struggle against the current. This struggle causes fatigue and leads to exhaustion and cramps.
For the past two weeks freediving on the northeast coast of Grenada it has been impossible to swim out more than 100 meters (300ft.) from the shore. The current is so strong and pulls east and south away from the shore. It has been like this in high and low tide.