By Brent Durand

Kelp.  It’s often where you aim to start a California dive.  It’s also something you swim around when on a long surface kick.  It looks magical in photos and every once in a while you get stuck in it.  Most importantly, it’s a fundamental part of our marine ecosystem here in California.

Giant Kelp (Macrocystis pyrifera) is found along the west coast of North America, as well as in several locations around the Southern Hemisphere.  It’s an algae that can grow up to 2 feet per day in ideal conditions, and reach a total length of 200 feet!  This rapid growth allows kelp fronds to grow from the bottom and create a living canopy on the ocean surface.  Below the canopy is a world of life we could talk about for days.

Kelp requires sunlight to carry out photosynthesis, but also grows best in nutrient-rich water less than 70°F.  During the summer in SoCal the water warms up and is less rich with nutrients so kelp beds will often deteriorate until winter/spring when the cold water is back.

Kelp is also a great indicator of ocean conditions.  If the kelp is standing straight up there’s probably no current, but if the kelp is at a strong diagonal be sure to plan your dive accordingly.  Because kelp beds attract so much marine life they’re sure to be great dive spots.  Lastly, if you keep an eye on the kelp at your local beach, you’ll begin to notice that the size of the canopy on the surface is a good indication of the tide.

Sources:  www.starthrower.org

Brent Durand is an avid California beach diver and ocean-inspired photographer.

The post Did You Know? Facts About Kelp first appeared on In Focus Underwater Photography Blog.

If you dive regularly in California, chances are you’ve gotten to dive with a sea lion.  Or was it a seal?  And were those seals or sea lions sitting on the buoy marking our way back into the harbor?

The California Sea Lion’s range is from the west coast of Canada all the way down to Baja.  The Harbor Seal’s range is from the Arctic down to Baja.  So odds are that you’ll see both if you spend enough time near, on and in the California ocean.  Here’s how to tell them apart.

Sea lions have large front flippers to help swim and glide through the water, which often look like little wings.  They also have rather large hind flippers that help them not only to swim, but to “walk” around on land at their haul-out.

Seals have much smaller, furry flippers but with larger claws, and smaller hind flippers to help them swim.  They have spotted fur.  On land, seals get around by doing the “worm” dance to scoot forward on their bellies.

Lastly, you can always tell a seal from a sea lion up close because the latter has small ear flaps.  A dive with either pinniped will have you exiting the water with a beaming smile across your face.

The post Did You Know? What’s the Difference Between a Seal and a Sea Lion? first appeared on In Focus Underwater Photography Blog.

The wetsuit.  Most of us use them, whether it’s year round, in summer when the water warms up or on vacation because at the end of a long dive even warm water feels chilly.  There are full suits, shorties, the farmer john and farmer janes, vests and beavertails to name a few.  But how do they keep us warm?

The basic principle is that a thin layer of water around the skin is quickly brought to body temperature and kept insulated from the cold water by trapped nitrogen gas inside bubbles in the neoprene.   Water wicks away heat much faster than air (the reason you get cold even in warmer water), so adding this layer greatly reduces the rate at which heat leaves the water layer around your body – the result being that your body loses less heat and you stay warm.

Minimizing water movement in and out of the wetsuit (via the neck, wrists, ankles, zippers and seams) is also critical to keeping a diver warm.  The goal is to find a snug-fitting, well-made suit that keeps the layer of heated water right where you want it – close to your skin.

Closed-cell neoprene was first used in wetsuits in the early to mid ‘50s and has continued to become more efficient ever since.  Wetsuits can be lined or unlined on the inside (the latter is popular for freediving), incorporate titanium or merino wool and many other cool features.

So next time you’re about to enter the water think of all those tiny nitrogen bubbles in the neoprene helping to keep you warm!

by Brent Durand

The post Did You Know: How A Wetsuit Works? first appeared on In Focus Underwater Photography Blog.