“Rockin” in the free Bay

As printed in: Latitude 38 – Sightings
June, 2009

In San Francisco Bay, there are rocks and then there are Rocks.
Alcatraz has long been known as The Rock, even though it’s an island.
Likewise, racers often refer to the Farallon Islands as the Rock Pile, or Southeast Farallon as the Rock. We’ve also heard Red Rock called ‘the Rock’ even though – again – it’s really an island.

Now that that’s out of the way, we can address the interesting query from a reader about where the ‘hazard to navigation’ rocks are in San Francisco Bay, and which ones sailors should be particularly concerned about. Oddly, this is the first time we’ve ever gotten this question and it took a bit of head scratching to come up with a list, since not all of the ‘hittable’ rocks are noted on charts, and not all notable rocks are hittable. Anyway, here’s what we came up with.

The Berkeley Reef – While the entire area from Cesar Chavez Park to Brooks Island is hazardous and off-limits there is a particularly nasty rock located Northwest of the Berkeley Marina, about a third of the way to Brooks Island. Normally just below the surface, it’s exposed only during extreme minus tides. The rock itself sits just East of the green piling marker (FL G 2.5s 13ft 3M “1”). At night, this light can be quite dim and is very easy to miss among all the background city lights. Warning: a strong westerly combined with current and tide can put you into the reef right out of the marina!

The Berkeley Pier – It presently extends 2.5 miles with a very dim and nearly indistinguishable red marker that blends into the cityscape at night. Currently, only the first 3000ft of the pier are maintained.
Beyond that is a 50ft gap for the passage of small boats then broken pilings between the ruins and beneath the surface that could impale your boat.

Blossom Rock – The sailing ship Blossom is hardly the only ship that came to grief on the submerged rock off the northeast ‘corner’ of San Francisco. But her 1826 demise gave the rock its name. Roughly 180 feet long by 100 feet wide, and lurking only a fathom underwater at low tide, Blossom Rock would continue to sink or damage ships for almost another half-century before a bid was awarded to blow the thing up. In a hugely elaborate scheme – and a hugely popular public event – a giant cofferdam was erected around the rock, the water pumped out,
23 tons of blasting powder (in barrels) placed and, on April 22, 1870, the switch thrown. The ensuing blast sent tons of mud and water high into the air, and was followed closely by the cheers, bell ringing and shots fired into the air by the estimated 50,000 to 60,000 people who had gathered on land and water to witness the event. Today, the Blossom Rock buoy still marks the spot, but only deep-draft commercial ships need worry about the 24-ft depth over what remains of the rock itself.

Harding Rock – The ubiquitous buoy used as a mark in so many racing courses actually marks the position of an underwater rock. Located roughly halfway between the Golden Gate and Angel Island, Harding is actually one of a trio of three rocks – Shag Rock and Arch Rock to the south being the other two. All three rocks have been blasted down to about 35 feet. Obviously, these pose no danger to yachts, or most ships except the deepest-laden tankers. About once a decade, the idea of lowering the rocks to bottom level – about 80 feet in that area – is discussed, but with a $20 million-price tag (as of 2000) it’s never gotten past the talking stage. Fortunately, the San Francisco Bar Pilots keep deep-draft ships well clear of the ‘three amigo’ rocks.
Incidentally, Harding Rock was named for President Warren Harding, who died in San Francisco in 1923. Also incidentally, the Little Harding buoy is a channel marker. There’s no rock under it.

Anita Rock – Yes, there’s a rock under that ‘permanent buoy’ located off Crissy Field. Its highest nub is inshore of the buoy, so always stay on the Bay side of the marker.

Mile Rock – Not really ‘in the Bay’ and hardly something you could miss, Mile Rock, located three miles outside the Golden Gate (but just one mile off the shipping lane, thus the name), nevertheless has a fascinating history. The lighthouse there traces its roots back to February, 1901, when, at night and in thick fog, the sidewheeler City of Rio de Janeiro hit rocks somewhere on the south side of the channel and sank in just eight minutes. The 128 souls (of 250 aboard) who went down with her make the Rio’s loss the worst peacetime disaster in Bay history. It was thought that if a lighthouse and fog signal had been available on her approach, the tragedy might have been avoided. Three years later, the job was bid out, but when the contractor and his crew were ferried out to the wind- and wave-swept rock, they all quit. So the powers that be went down to the Embarcadero and hired a bunch of sailors. After lots of slipping and sliding, the sailor crew managed to blow the top of the rock off and lay the foundations for what, at the time, was said to be one of the most handsome lighthouses on either coast. After it was automated in the mid-’60s, the pretty top half was cut off to allow for a helicopter pad. All that remains is the squat orange and white structure you see today. And just so you know, inshore of Mile Rock is a minefield of rocks that has claimed many boats and ships over the years. Do not go in there.

Red Rock – Red Rock itself is an island, not a rock. But there are lots of rocks around it that are hittable, and people do it all the time when the island is used for a racing mark. So steer well clear.
Red Rock has a fascinating history that includes manganese mining (that’s why it’s red), a hermit who lived there and claimed the island as his, and an early survey job that ended with three counties abut- ting each other there – Marin, Contra Costa and a long tendril of San Francisco County still intersect at the island’s highest point.

Castro Rocks – Castro Rocks, an outcropping just north of the Richmond Long Wharf, is another boat biter. There’s a buoy marking them, but race boats like to go inside the buoy to avoid the ebb. If you’ve ever been there during a low tide, you’ll know that’s a dicey thing to do.

Cone Rock – Located in Richardson Bay, Cone Rock is actually made up of three points, and the Coast Guard built their light on the highest one. The others are on the south side. The most southerly of the ‘points’ sometimes breaks the surface at very low tide.

Elephant Rock – The only way you could hit Elephant Rock by mistake is if the boat was on autopilot and you were below making lattes. (D’oh!) Located a literal stone’s throw off the Tiburon shoreline, Elephant Rock, attached to land by a small bridge, is a popular fishing spot and great photo-op spot for CYC races.

The Needles – Again, you’d have to really be out of it to hit the Needles, those picturesque rocks tucked close to shore between the North tower of the Golden Gate and Horseshoe Cove. So keep your eyes open and stay well clear.

“Little Alcatraz” – Located a few hundred yards west of the north tip of Alcatraz, this little rock is awash at high tide and well out of the water at low. In other words, you can plainly see the rock or swirl above it during all tidal cycles. Despite that, it probably accounts for more damage to modern boats than any other single rock in the Bay, with sometimes several boats a year (at least that we hear
about) smacking into it.

“Irv’s Rock” – This rock, located near the end of the San Francisco Marina jetty, was named for the late Irv Loube, who hit it during a Big Boat Series in the ’70s in one of his Bravuras. There used to be a buoy there to mark the suspect area, but we haven’t noticed one in awhile, nor have we heard reports of further strikes, so this rock – or whatever it was – may have moved or shoaled over.

“Stormvogel Rock” – Again, an unofficial name for an underwater speed bump located between the South Tower of the Golden Gate and Fort Point. It was named for the beautiful 75-ft South African ketch Stormvogel, which hit it sometime back in the ’60s.

These are the main ‘rocks’ that we could think of that Bay sailors should be aware of. (Did we miss any? Let us know.) Of course, there are many other unnamed rocks or outcroppings in our local waters, but most are off the beaten track or so close inshore that it would be foolish to sail there in the first place. One final caution: don’t sail too close to points of land like Belvedere Point and Point Blunt on Angel Island, as there are rocks well out into the water in those areas. Both these points are marked by buoys for this exact reason. In those areas – and any other point with a buoy close offshore – always pass outside the buoy.

Don’t say we didn’t warn ya!

This Post Has One Comment

  1. Josh Barrows

    Thanks for posting :-)

Comments are closed.