SoCal Channel Crossing
Ship's log · next 7 days · Marina del Rey → Avalon
A passage is only as calm as its roughest stretch, so each hour takes the worse of the two ends — then swell can knock an hour down a level. A run of green is your window.
This week's read
Sat is the day — 24 green hours
On the Marina del Rey → Avalon run, the rough hours this week sit mostly on the arrival end. Swell stays small or long-period all week, so wind alone sets the colors. A marine layer is in play — some hours run under a mile of visibility; the fog hatch marks them, and green seas don't help if you can't see the traffic. Mornings run calmest before the afternoon breeze fills in. ECMWF and GFS disagree on Sun, Mon, Wed, Thu — treat those colors as lower confidence.
Extended outlook · days 8–16 · wind only
Daily max wind, worst of both ends, blended model only — no swell this far out. Past ~10 days, lean on the seasonal pattern below.
Across the year
When the season cooperates
Peak flat water: late June through September — warm, light winds, small long-period south swell. Spring brings windy afternoons; winter is roughest, when NW swell events and Santa Ana winds move through. One rule holds year-round: mornings are calmest, afternoons build — early departures win in every season.
Notes to mariners
Light wind
Under ~8 knots the surface stays glassy to gentle. Past 13, whitecaps — hold off.
Long-period swell
Small swell at 12+ seconds rolls gently under a hull and is left alone. A steep set (4 ft at 8 seconds or less) or anything 6 ft and up knocks the hour down a level.
Worst end wins
The crossing is scored by its roughest stretch — pick your two ends on the chart and the reading takes the worse of them, hour by hour.
Summer south swells
Hurricane season off Mexico sends long-period south swell up the line. South-facing shores get sketchy fast, so a sizable swell out of the south knocks hours down at the backside spots and raises a watch flag.
Santa Ana winds
High pressure over the Great Basin circulates clockwise and drives desert air downslope to the coast, heating as it falls. When the source air is cold — snow line low — it arrives merely warm and blows hardest. Hot on the mainland, warm at the island, and the lee flips to Catalina's south side. The watch flag reads wind direction and the freezing level to call it.
On the water · quick reference
VHF 16
Hailing and distress, monitored by the Coast Guard — keep a listening watch underway. Working channels after you make contact.
Harbor channels
Avalon Harbor Patrol works VHF 12 — call before entering for a mooring assignment. Two Harbors Harbor Department works VHF 9. Most mainland harbormasters answer 9 or 16.
Weather broadcast
NOAA Weather Radio runs continuously on the WX channels (Los Angeles on WX1, 162.550 MHz) — same zone forecasts shown on this page, read around the clock.
San Clemente ranges
The Navy announces live-fire closures and hails traffic on VHF 16. Check the schedule at scisland.org before committing, and expect a call if you wander into an active range.
Float plan
Tell someone ashore your route, ETD, ETA, and boat description before any crossing — and close it out when you arrive. The Passage plan line above gives you the numbers.
Notice to Mariners
Free membership — crossing alerts and more SoCal channels, when they publish.