How To Read A Dive Forecast

Many divers are also loyal SURFERforecast premium members.

“As an avid Southern California scuba diver I find these maps invaluable for planning my diving days.

The easy to interpret interface and the accuracy make this site a dive planning must have. The “blues” don’t get us divers down! The darker the better for us .

Thank you Surfable & SURFERforecast” – Gayle G

Currents

Underwater currents refer to the movement of water in a particular direction. They can be mild or strong, depending on various factors. Strong currents can affect the dive plan, change the specific route, affect control, and even the duration of the dive. When diving with strong currents, it's necessary to plan accordingly and seriously consider things like drift diving techniques.

Tides

Tides are the rise and fall of sea-level water due to the gravitational pull of the moon and sun. High tides increase the movement of water. This affects visibility and dive sites. Conversely, low tides affect underwater features. Check the tide table for specific dives. Diving should be chosen during slack tides (when the current is minimal) for better visibility.

Visibility

Visibility refers to how far one can see underwater. Clear water enhances the diving experience several times. Good visibility allows you to see interesting features under the sea and navigate safely. So, choose a forecasted time for diving to enjoy excellent visibility. 

Clarity: 

Water clarity determines how far light can penetrate through the water. It affects underwater visibility and is crucial to aquatic ecosystems. Clear water allows sunlight to reach deeper, which is crucial for plants. This clarity brings out the underwater beauty in a fascinating way. Therefore, the diver must first choose a dive site with high clarity. Water clarity is often used to describe underwater visibility.

Nearshore wind

Our nearshore wind and weather animated maps from Windy to help you select ideal dive conditions.

Entry/Exit Point & Tides and Surge Report

Currents and tidal surge are another important factor for ideal dive conditions. *Be sure to do your research about entry/exit locations for each dive site, because tide can have a huge impact on the conditions as well. There is a good in-depth article from Dive Training that goes more in depth about what and how to be more informed when planning your dives.

Upwelling

Upwelling is a process where cold water rises to the surface due to strong winds. Upwelling occurs when winds push surface water away from shore and deep water rises to fill the void. For divers, the upwelling zone presents both challenges (such as changing temperatures and reduced visibility).

Live Conditions and 10-Day Forecasts

• Southern California
• Northern California
• Hawaii
• North Shore of Oahu

Here is an example of smaller surf and better dive conditions in Orange County, San Diego and La Jolla, San Diego.

The best dive conditions for beginners

If you’re a complete beginner, you might want to dive in the warmest water possible. The warmest water is usually in the Summer in California or year-round in the tropics, and it’s easier to get used to diving in warm conditions. The best dive conditions for beginners are warm water, minimal current and a low amount of (large) marine life. This will allow you to get used to scuba in a low-pressure environment. You might also want to start with freediving or snorkeling, which will allow you to dive without getting used to breathing underwater through a mouthpiece.

The best conditions for enjoying marine life

When you decide to dive with a specific goal in mind, it can make your experience much more enjoyable. If you want to dive to see as much marine life as possible, you’ll want to choose the best dive site and conditions for those sea creatures. It goes without saying that the ocean is very diverse and each stretch of coast will reflect that diversity in marine life.

Tropical water is usually a good choice, as the temperature of the water is ideal for a wide range of marine life. You might also want to dive in the morning, as this is when many creatures are more active. Get as far away from human activity as you can, and take advantage of the natural light at that time of day.

The best conditions for clear visibility

Most divers are obsessed with seeing as much as possible underwater, so clear visibility is always a high priority. The best dive conditions require minimal current, a lot of sunlight, no wind, no surf swell and no tidal surge. See the 10-Day Forecasts for California and Hawaii to help you plan your dive.

The best conditions for a safe dive

For a safe dive, you’re probably best off looking at diving in temperate/warmer water. Tropical water is warm and doesn’t require a thick wetsuit, like you would in California. *Although many divers still use a 2-3mm wetsuit for dives longer than 10-20 minutes. Don’t forget to ask locals about currents other zones that are tide dependent.

The best conditions for night diving

The best dive conditions for night diving are warm water and finding a night dive outfitter to help you plan the dive. You’ll also want to dive in a location where there is a lot of marine life moving around. Some sea creatures are nocturnal (think Octopus, Moray Eel, Polyps, etc). Night dives are a great way to experience the bioluminescence some creatures have (glow in the dark). The best time for a night dive is at dusk or a few hours afterward. Essential gear: dive light or underwater torch, whistle, strobe light, backup light and a few glow sticks.

What is a dive report?

A dive report is an aquatic adventure diary. It usually includes dive details related to underwater conditions and weather, depth, visibility, and marine life experiences.

Marine life observations, any significant events or discoveries that occurred during the dive, photos or videos, etc. are shared in this report. Dive reports are often shared within the diving community to help other divers plan dives and get accurate information.

Other Factors

What do you need for scuba diving?

You must be proficient in swimming before diving. Knowing how to swim and drowning in water are not the same thing. Prior training in diving is required. 

You must have an understanding of how scuba gear works, what to do if it stops, and the safety protocols for communicating with other scuba divers underwater. In the ocean, communication happens through gestures rather than spoken words.

Double check your equipment.

Be aware of the weather conditions. 

Familiarize yourself with the tides in the ocean. 

Avoid diving alone without an instructor.

Take a course in this subject from a good training center. This course covers diving techniques, safety procedures, basic precautions, and wildlife conservation. Before choosing a diving training agency, it’s essential to research their level of expertise.

Dive in an easy place first. First, you need to master yourself by diving in a comfortable and safe place like an ocean beach, sunset, lake, etc.

Take precautions: Take precautions while diving, such as depth, contact with a diving partner, water condition, etc. Plan diving according to your certification level.

When to avoid diving?

If you are not physically fit, then this is not recommended for you. If you have significant medical conditions such as recent major surgeries, heart problems, a history of stroke, respiratory issues, a persistent cough, or high blood pressure, you should avoid diving.

Diver Down Flags:

These flags serve as very important safety equipment to signal diving activities to other boats and watercraft. It is again of two types:

1. Diver flag: It is a rectangular red flag with white diagonal stripes. It indicates the presence of divers at a place.

2. Alpha Flag: It is also known as the international code flag "A.". It is flown throughout the ship during diving. This blue and white pennant flag signals to other vessels that the ship is engaged in diving operations.

Colors underwater: 

As the water penetrates deeper, its color changes due to different waves of light filtering through the water. The order of color change is:

Red: Disappears as deep as 15 feet (5 meters).

Orange: Begins to fade at 25 feet (7 meters).

Green: Becomes less vivid at 70 feet (20 m).

Remember, safety and awareness are key, whether you're flying a flag or exploring ocean colors.