Scuba diving during the daytime is a fascinating activity that can, and often does, incite an array of emotions. Diving at night opens up a completely transformed world and amplifies these emotions. The addition of artificial light is necessary for divers to see under water during a night dive. This additional light; however, limits divers field of vision compared to diving during the daytime. For these reasons, night diving is classified as limited visibility diving.
It is highly recommended that divers participate in specialized training before diving at night, or in limited visibility water. Diving in limited visibility requires the diver to focus more intently on his dive systems and mental acuity. Divers will also need to employ navigation techniques in order to determine and maintain their underwater position.
Divers choose to dive in limit visibility water for many reasons:
Night Diving — Night diving allows us to observe thousands of species in new and unique situations. Fish seen during the day are often sleeping or resting and are easy to observe. Nocturnal life we don’t normally see during the day come out of hiding to search for food and socialize. Additionally, we are able to observe bioluminescence that we cannot see during the day.
Limited Visibility Water — Divers define limited visibility differently based on their personal experiences. For the purposes of this text and your SNSI training, limited visibility diving is defined as water that has horizontal visibility of less than ten feet/three meters. Limited visibility diving is popular in areas where there is no alternative, typically inland lakes and rivers.
Limited visibility diving is also common in certain areas or where specific tasks are conducted. These often include research and archeological areas, wreck sites, and when conducting searches.
SNSI requires that SNSI Advanced Open Water Divers be trained in Night and Limited Visibility Diving. While night diving and limited visibility diving are very similar, there are notable differences.
For instance, diving at night often takes place in very clear water that has extremely good visibility when artificial light is introduced. This type of situation would be handled differently than a dive conducted in water with three feet/one meter of visibility. For this reason, the SNSI Advanced Open Water Diver Course treats these as two distinct diving activities.