Submarine canyons are fascinating geological structures that are gashes in the continental shelf that bring deep water and its creatures close to shore. They serve mainly to act as transport corridors for sand and sediment to find its way down the continental shelf as longshore currents push the sand along the beaches. For us underwater explorers, they make excellent dives for the interesting animals and excellent deepwater training. Upwelling brings cold nutrient rich waters close to shore that in turn support unique ecosystems quite different than the typical Southern California reef and kelp forest.
Along the Southern California coastline, there are a total of five submarine canyons that are close enough to the mainland to make them easy beach dives. They are located at, from south to north, La Jolla, Newport, Redondo, Point Dume and Hueneme. While not as interesting as the La Jolla, Redondo and Point Dume Submarine Canyons, the deep drop at Port Hueneme definitely has its strengths as a dive site, mainly the nearby reef and pismo clam beds.
For your beach entry you will be heading to La Jennelle Park at the north jetty of Port Hueneme. Entrance to the park is at the intersection of Sawtelle and Ocean Drive. The park gets its name from passenger liner La Jennelle that ran around in 1970 and floundered. Impossible to remove from the beach, the superstructure was removed and the hull filled in with rocks extending the jetty to the northwest. Only a small portion of the wreck is visible today and most of that from the surface. Any underwater features of the wreck are in shallow churning waters and not worth exploring.
There is a small parking lot at the beach park but no facilities. Sometimes the short road to the parking lot and the parking lot is closed due to blowing sand so you may have to park on the street and walk further. Gate to the parking lot closes promptly at sunset. The rocky jetty is to the south of the parking lot. If you have a 4-wheel drive, you can continue across the sand parallel to the fence that divides the public beach area from the Navy CB (Sea Bee) base. This will take you right down to the entry point. Without a 4-wheel drive, you have to hoof it from the parking lot but it is a short walk.
You have three choices for water entry, but one is illegal. The first and most commonly used is directly off the northwest side of the jetty. Surf has to be small to make this rock entry and exit. Always check out the surf report online before heading for the beach. Once there, check it out carefully before donning your gear and heading for the water. A second choice is to enter the small cove created by the La Jennelle extension of the jetty. The cove faces directly into the prevailing surf and the water is shallow, so surf can be just as much as a problem here as off the rocks, plus it is a long swim to the canyon. The third choice for entry is into the calm waters inside the jetty. But this is illegal and divers have been cited even arrested. The choice is yours.
For many divers the main event is the rocky jetty that extends outward along the mouth of the harbor at Port Hueneme. Here the rocks drop off quickly to 20 feet and then moderately to 45 feet at the tip of the jetty where they make contact with the submarine canyon slope of sand and mud. On the submerged rocks is a plethora of animals. The upwelling from the canyon supports a large amount of marine life. My favorite is the abundant gorgonian, California’s answer to soft coral. Within the golden fans are large sheep crabs, a variety of mollusks, and octopus. Like many rocky jetties along our coast, this is a good habitat for lobster. Fish life includes rockfish, barred sand bass, scorpionfish, cabezon, and garibaldi. If the surge is not too strong, spend some time up in the shallows with the zebra perch, opaleye and surfperch. Depending on the season, the rocks here occasionally support a small kelp forest with calico bass.
At the tip of the jetty you will come to the canyon drop immediately. Be sure to use your navigational skills to avoid wandering into the mouth of the harbor. In the canyon you will find debris with more scorpionfish, rays, small octopus, unusual nudibranchs, and moon snails.
Some divers choose to complete their dives exiting the water around the northwest side of the rocks in the cove, but once again be aware that the surf here can be tough.
One final option here is a second dive is a visit to the pismo clam beds in the sand to the northwest of the rocks. Pismo clams are the tastiest in California and here they are abundant. Look for them in 15 to 20 feet of water with their siphons just sticking above the sand. Once you found two or three, you have found dozens. You must have a fishing license and regulations apply.
Dive Spot At A Glance
Location: At the northwest entrance of Port Hueneme.
Access and Entry: Short walk across sand (or drive for a 4-wheel drive) to a rocky surf entry. If parking lot is closed due to blowing sand it will be a longer walk.
Skill Level: Intermediate or better with rock surf entry experience.
Depths: 20 to 80+ feet
Visibility: Fair, averaging 10 – 15 feet.
Photography: Good especially for macro with lots of subjects on the rocks or in the canyon mud and sand
Hunting: Good for lobster on the rocks and clams on the nearby sand off Silver Strand Beach.
Hazards: Surf must be small to dive here. Stay out of the harbor mouth.
Conditions: Online at http://cdip.ucsd.edu/?nav=recent⊂=nowcast&xitem=vent_hs.
