The Hazards of E.S.S.
Extreme Shallow Snorkeling may entail untold hazards. Here are a few, and some tips on managing them. Most importantly, always remember that safety is #1. Never put yourself or members of your party at risk, always be aware of the environmental conditions and your own limits. Be prepared, and be prepared to skip your E.S.S. if the conditions or location are dangerous.
Swell, Surge and Tides
Swell and surge are both terms related to waves. Swell typically refers to the series of wind-generated surface waves on the ocean or a large body of water. These are typically directional reasonably consistent over short periods of time. Knowing the size and direction of the swell can help you find areas that are relatively sheltered or know when Extreme Shallow Snorkeling is inadvisable. You can check the local swell at sites like Wind Guru.
Surge refers to the up-and-down or back-and-forth movement of the waves. Surge may push you back and forth or lift you up and down. It is typically related to the size and direction of the prevailing swell, but may also be impacted by the local topography. For example, the surge is often stronger near rocks or the shore because these formations are blocking the motion of the swell.
Tides are the rising and falling of sea level due to gravitational forces, primarily that of the moon. They vary widely around the world in their size and typically there are two high and two low tides per day in most places. While the oscillation between low and high tide is often slow, in some areas, tides cause fast and powerful currents. Most often, this happens at the narrow mouth of a lagoon or other channel connecting a body of water to the sea. In these areas, tides cause large amounts of water to pass through a narrow space, greatly magnifying the effect of the tide.
Depending on your location, there may be a variety of aquatic hazards to consider. Some are biological, like sea urchins and fire coral, while others may be geological (sharp rocks) or man made (broken bottles, rusty metal). It is important to be aware of possible hazards in your location and avoid them. The danger of many of these aquatic hazards is amplified by extremely shallow conditions, which are more likely to put you in contact with underwater hazards.
Entries and Exits
The transition between land and water may be easy, like on a sandy beach on a calm day, or substantially more difficult if entering the water from a rocky area. Before entering, underwater hazards may be difficult to see, and the shoreline is typically where waves have the biggest impact.
If you can, look in the water before you get in to judge the safety of your entry point. Monitor the waves for a few minutes to identify the general pattern and frequency of the swell. Identify a safe exit point before entering. When entering from a rocky shore, time your entry to avoid being hit by a big wave, and move quickly to a safe location (i.e., don’t hang out right next to a rocky shore if the next big wave will slam you right into it).