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2006/08/23

Diving 102: California Kelp Diving and the Kelp Crawl

Equipment

* Knife: Used to cut kelp during entanglement. During a dive, keep the knife in the sheath on the inside of your calf, on a BCD pocket, on the BCD shoulder (small knife), or anywhere it will not get tangled.
* Compass: If you can navigate, you will never need to kelp crawl.
* Snorkle: Use this to conserve air when doing the kelp crawl.
* Dive Light: This is optional, but under the kelp canopy it can be quite dark.
* Fish ID Chart: This is optional, but there are many things to see.


Kelp Facts
Kelp belongs to a large group of living organisms called algae (singular: alga) in the Kingdom Protista (think of the slime in a pond). Kelp is photosynthetic plant-like life. That means it gets its energy from the sun which is uses to create food by turning CO2 into sugars. Every algal cell potentially has the ability to photosynthesize and there is generally no complete specialization of different parts of the algae. The structure of kelp is very basic: holdfast (root-like organ that cements/anchors the kelp to rocks or other solid substrate), stipe (trunk-like or limb-like flexible shaft that connects the holdfast and the blades/bladders), bladder (air filled sacs that bouy the kelp towards the surface [they are sometimes connected between the stipe and blade, othertimes they are part of the stipe]), and blades (leaf-like appendages where most photosynthesis occurs). Kelp requires a solid, unmoving surface for its holdfast attachment. This means that they must anchor to rocks or rocky bottom material. To survive, kelp needs to attach to a substrate between 6-30 meters deep in clear (read that as not dark and murky) cool water.

Kelp Diving Basics
The most critical things to keep in mind when diving in kelp is to check your air supply regularly and navigate your plan. I would also never dive in kelp without a knife and snorkle--both are needed if you must use the kelp crawl. When diving in kelp, simple out-and-back plans work the best. This may seem like a very limiting plan, but kelp forests are usually divided into smaller sections called beds. The kelp beds are defined by where there are rocks used to anchor the kelp and where rocks are not found. In the space between kelp beds, it is common to find sand channels (kelp needs a solid unmoving surface to anchor to or else it will be wash ashore during storms). Use these channels as trails to get out to deeper water (surface swim). While at the surface, get a heading for your out-and-back trip into the kelp bed. Descend on the outside edge of the kelp bed--avoid descents while in kelp (tangle hazard). Turn toward your heading into the kelp bed and start your out-and-back dive. Return on the reciprocal course back to the sand channel and navigate back to shore or the boat.

The Kelp Crawl
If you find yourself in the middle of a kelp bed either due to poor navigation and/or low on air, the kelp crawl will serve you well to get you back to shore. The kelp crawl is no substitute for good dive planning, good navigation, or good air monitoring.

First things first, remain calm-cool-and-collected, power/orally inflate your BCD, switch to your snorkle (you have one handy, right!?) and tuck all of your gear away (anything that dangles) to lessen tangles. That means clip your light to your vest, reel in your SPG and stow your gear as compact as possible. Second, pull out your knife and hold it in your right hand (this keeps your left hand free to work your BCD auto inflate/deflate). Next, get both hands out in front of you and start slow methodical kicking. Your arm movement is the most important aspect of a correct kelp crawl. With alternating arms, push the kelp under your body and glide over the top of the kelp canopy. During a kelp crawl, plan the shortest path through the kelp. This doesn't mean a straight line to the beach or boat, but the shortest line to get you out of the kelp. Send the diver with the most experience, knowledge, skill, endurance to the front. This should make it easier for the other diver. Lastly, if the kelp crawl is taking too long, trade point position or rest and take it slow.

If you get tangled, either cut yourself free or have your buddy do it for you. Giant Kelp has very high tensile strength so you may be unable to break it by pulling; however, sometimes it can be snapped in two like a pickle by bending. If you are without a knife, you can easily bite through kelp stipes. Never roll around in kelp. Rolling in kelp is for otters. If kelp gets around your tank yolk or first stage, you will have a difficult time getting out by yourself. Again, if you get tired before you're out of the kelp, inflate your BCD and rest. The kelp crawl is a very tiring activity and it will teach you to be a better planner and navigator. When all else fails, drop your weight to help keep you afloat when tired and yell/signal for help to get some attention.

Kelp Classification
Kingdom: Protista
Division: Chromophyta*
Class: Phaeophyceae
Order: Laminariales
Family: Lessoniacea
Genus: Macrocystis
Species: Macrocystis pyrifera (Giant Kelp)

Kingdom: Protista
Division: Chromophyta*
Class: Phaeophyceae
Order: Laminariales
Family: Lessoniacea
Genus: Nereocystis
Species: Nereocystis leutkesana (Bull Kelp)

Kingdom: Protista
Division: Chromophyta*
Class: Phaeophyceae
Order: Laminariales
Family: Lessoniacea
Genus: Laminaria
Species: Laminaria spp. (Kelp)

*the Division Chromophyta is the new term used for the old Division of Phaeophyta

Links to Kelp Information
http://www.biology.ucsc.edu/people/raimondi/readdie/index.html
http://diver.net/seahunt/d_kelp.htm

Document Source: http://Quashnick.net/scuba/university/diving102.html
Design and Content: Stephen Quashnick

Posted at 08/23/06 on 2006/08/23 by Stephen - Category: Northern California Diving -
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