Northers in the Sea of Cortez: Anchors, anchor drag alarm, and watching out for other boats dragging

In the southern Sea of Cortez, there are many anchorages that seem to be well protected for Winter's northerly blows. Almost all the bays on Islas Espiratu Santo and Partida face to the southwest/west* with no opening to the north/northwest/northeast. When a "norther" blows, one usually sees no swells and at most only small wind waves when anchored in these most of these bays. However, strong winds still often come across the low-lying heads of the bays; in some bays (e.g., El Cardonal, Caleta Partida; Ensenada de la Raza) the surrounding mountains seem to accentuate the north winds and these anchorages can be very gusty (albeit, with no waves).

Last year, it took us a while to get used to anchoring in Northers in the Sea of Cortez. Very often, the boat is straining against the anchor rode and, when gusty, the boat yaws back and forth.  When really blowing, the boat is really "hanging on" to the anchoring system.

This is so different from our anchorages back home in British Columbia, where we usually have excellent protection (often from all points of the compass) from both seas and winds.

Happily, with northers here in the islands in Bahia de la Paz, there are no seas (waves) to pull the anchor out and the sandy bottom is good (so the anchor is well dug in).  With a good anchoring system, good anchoring practice, and a good anchor alarm (because dragging anchor can happen to anyone), there is little to worry about. We have all-chain rode and a 25 kg Rocna anchor. We always try to anchor with a scope of at least 4:1 (chain length let out is 4 times the distance of the depth at high tide plus the height to deck of boat), and often 5 or 6:1, if the winds are really forecast to blow. (Happily, with few boats here in the sea of Cortez in Dec-Apr, there is usually ample room for such scope). Our anchor alarm is the Vesper Watchmate 850 AIS system -- this is a standalone AIS system that uses very little power (<0.3 amp) which we've been very happy with as an AIS system. The anchor watch feature is a real bonus.

Our 25-kg ROCNA anchor

Vesper Anchor Watch/Alarm

Of course, once you are anchored securely, it doesn't mean others have done the same thing. Since leaving British Columbia in August 2013, we've had three boats near us drag 50-100 meters, with one boat at Treasure Island in San Francisco Bay actually hitting us (luckily, we had a fender out so no damage). (Perhaps a coincidence, but all 3 boats used "plough" type anchors: 2 CQRs and 1 Delta.)

Why is this charter cat anchoring right in front of us? Answer: to drag onto us and snag our chain

The other day, anchored in a light  (~10 kn) norther in Bahia San Gabriel, we watched a large power catamaran, obviously a charter boat, drop anchor 100 meters directly in from of us (why do they always do that in a huge, uncrowded bay?). Normally, 100 meters away is an OK distance to anchor, but we we are always suspicious of charter boats. One hour later, we saw they had dragged at least 90 meters to now be within 10 metres of Pelagia. After we caught the Mexican charter skipper's attention -- we were yelling and waving our arms --  he promptly started both his engines and motored across our bows, immediately dragging his anchor across our anchor chain; he then reversed and upon pulling up his anchor, there was our anchor chain caught up with his anchor. It took him a while to get our chain off his anchor, all the while drifting only 3-4 meters off our bow. Lucky the northers were light! He then motored away, re-anchoring much farther away (a couple hundred meters). Nevertheless, we kept our radar on him until he up-anchored and left a couple hours later with his charterers for La Paz.

When anchored, it pays to keep an eye on others.



* These bays are open to winds from the Southwest/West; these "Coroumel" winds occur in Bahia de la Paz and can (and do) occur anytime of the year. For example, see SV Cadenza's recent Winter experience in Gabby Bay (middle part of http://www.sailblogs.com/member/svcadenza/?xjMsgID=343029)