This Week on the Water: Labor Day Weekend, Warm Blue Offshore, and a Crowded Coast

It is Labor Day weekend, and the water is doing exactly what you would expect for early September - warm, blue offshore, and worth the effort if you pick your spot. The late-August blow that browned out the coast has settled down, the diving is coming back, and the warm water has the coast loaded with fish worth putting a shaft in. It is also one of the busiest boating weekends of the year, so staying visible and staying safe in heavy boat traffic needs to be front of mind. Here is how the week is shaping up and how to dive it smart.

THE SETUP THIS WEEK

The heat is still on. Surface temps are holding warm across Southern California, and it is warm well down the water column - divers have been logging low-70s in the shallows and water still in the 60s at depth. That warm lens on top means a strong thermocline; plan for the deeper number, not the surface, and expect a real temperature break when you drop under it.

Green inshore, blue offshore. The classic warm-season split is in full effect: plankton-y green water hugging the coast and clean blue water out at the banks and islands. If you want visibility, the play is to get deep, get out to the islands, or get offshore. The inshore is streaky - protected areas cleaned up first after last week's wind and chop, while the exposed south-facing spots stayed surgy.

Morning marine layer. Thick fog has been sitting over the coast in the mornings. It makes the surface look flatter and cleaner than it actually is, so do not read the conditions off the parking lot - and it is one more reason to be careful with boat traffic this weekend (more on that below).

WHERE TO DIVE THIS WEEKEND

San Diego / La Jolla: The Cove, the Shores, and the Marine Room are morning games and swell-sensitive. On a calm, small-swell dawn they can clean up nicely; depth off the kelp and the canyon edge is the more reliable bet for blue water. If a south swell fills in, expect the shallows to brown out fast.

Orange County / Laguna and LA / Palos Verdes: The south-facing coves and points - the Laguna coves, PV, Crystal Cove, Treasure Island - are the first to get surgy when south energy shows up. Dive them on the calm mornings and have a protected backup ready. Catalina remains the standout for boat divers, with the warmest, cleanest water in the region.

Central Coast / Monterey: Cooler and greener than the south, but September and October are traditionally the clearest months up north. Point Lobos and the Breakwater fish well on the calm days - watch the afternoon wind and the odd north swell.

THE SPEARFISHING: BLUEWATER AND THE KELP

The warm water has set up one of the best stretches of the year for divers. Here is what is worth hunting right now, from the paddies offshore to the kelp along the coast:

• Dorado (mahi) on the kelp paddies. The prime bluewater target right now. They stack under floating kelp offshore - find a good paddy, slip in quietly, and they will often come to you. A flasher and a float line earn their keep.

• Yellowtail on the kelp and structure. Still around on the points, the hard structure, and the offshore paddies. The bite has slowed inshore, but a quiet approach on a clean-water day will still put fish in range of a shaft.

• White seabass on the deeper kelp. Quieter than the spring grade, but a low-light morning on the outer kelp edges is worth a slow, quiet drift. This is a patience fish.

• Calicos, sheephead, and reef fish inshore. When the swell or the crowds push you off the blue water, the nearshore reefs are productive and a good way to keep the day simple and safe.

• The exotic stuff, for experienced bluewater divers only. The warm water has marlin and tuna in range offshore. That is advanced, big-fish hunting that demands the right crew, the right gear, and a boat running a flag with a dedicated spotter - not something to freelance in holiday traffic.

Species, sizes, and seasons change - confirm current bag and size limits and gear rules with CDFW before you take anything, and only hunt within your training, your breath-hold, and your limits.

WARM-WATER STRAYS - AND A CALL TO ACTION

The El Nino-flavored warm water keeps pushing tropical visitors north. Divers have been reporting mantas and roaming hammerheads offshore, triggerfish caught right at the Marine Room, and a thresher cruising through La Jolla. None of it is cause for alarm - it is a sign of just how warm and how far north this water has come.

Warm-water strays like this scalloped hammerhead are part of the El Nino signature this year - divers have reported hammerheads roaming offshore. Photo: Kris Mikael Krister, via Wikimedia Commons, CC BY 3.0.

If you photograph something that does not belong, report it. The Scripps Institution of Oceanography Marine Vertebrate Collection runs a community effort to track unusual fish showing up in our waters. It is a great way for divers to contribute real data - get a clear photo, note the location and date, and send it in. We are the eyes on the water, and a warm-water year like this one is exactly when those sightings matter most.

BOAT TRAFFIC: THE WEEKEND'S BIGGEST HAZARD

This is one of the busiest boating weekends of the year, and heavy boat traffic is the single biggest hazard you will face out there - bigger than anything in the water. Powerboats, jet skis, and holiday renters are everywhere, plenty of them not looking for a diver's head in the chop, and the morning fog only makes it worse. Assume boats do not see you, and dive accordingly:

• Fly a dive flag and stay with it. Tow a float with a bright, legal dive flag, keep it close, and run a float line off your gun so you are never chasing gear away from your flag.

• Surface next to your float, not away from it. Come up beside the flag where a boater has a chance to see it. Never pop up in open water in a boat lane.

• Keep your head on a swivel on the surface. Look and listen before you surface and scan for traffic every time you come up. In the morning fog, listen for engines you cannot see yet.

• Stay out of boat lanes, channels, and harbor mouths. Pick spots away from the traffic. If a spot is a zoo with boats buzzing it, move on - no fish is worth getting run over.

• Bluewater divers, run a proper setup. Offshore, your boat should fly its flag, keep the engine ready, and post a dedicated spotter on the divers at all times. Drift with the boat, not away from it.

• Give the sea lions room. They have been aggressive around the bait this summer - keep your distance, especially with a stringer of fish on you.

And keep the domoic acid bloom in mind. The warm water has been feeding harmful algal blooms up and down the coast. Check the current California Department of Public Health (CDPH) advisories before you eat anything you take, especially shellfish or whole small fish, and give any distressed marine mammals plenty of room.

LOOKING AHEAD

Two things on the near horizon. The groundfish fishery seaward of the 50-fathom line stays closed through September 30 and reopens October 1 - know which side of that line you are on if you are dropping deep for rockfish and lingcod. And the recreational spiny lobster season opens October 3, so this is prep month: scout your spots, service your gear, and make sure your license and report card are squared away before opener.

THE BOTTOM LINE

Warm water, blue offshore, a busy coast, and a pelagic season at its peak - this is a good week to be on the water if you plan around the crowds and the swell. Dive the mornings, go deep or offshore for the clean water, fly your flag, and respect the bloom. Enjoy the long weekend and dive safe.

For real-time visibility and conditions predictions across every California dive spot, check conditions.spearfactor.com. Conditions change fast - always verify current forecasts, CDPH advisories, and CDFW regulations before you dive.