This talk of setting depth alarms at 80 ft sounds pretty funny to the Chesapeake Bay sailor's ear. Here, the major shipping channels are dredged to maybe 55 ft, and most of the rest of the middle bay is 20-25 ft, totally leaving aside the creeks, rivers and inlets. I did charter once out of Anacortes, though: the west coast is a totally different beast.
As I’ve mentioned, I lived in FL for 11 yr and sailed my Pearson 30 w/ 5-ft draft extensively in areas between Dunedin and Pine Island Sound/Tween Waters, in and out of the ICW, home ported in Tampa Bay @ St. Petersburg where the AVERAGE depth of the Bay is about 20 ft. But, I saw lots of water 12 ft and less, particularly along the eastern shore of the Bay. There, we regarded 12 ft as good anchoring depth, 10 ft even better. Hardly anyone wanted to anchor in, my God!, 20 ft
. If you did touch bottom, you were usually in mud or, at worse, hard sand. No rocks around except for rip-rap.
Our first charter to the PNW in 1993 took us from Anacortes to Sucia, then across the Haro Strait into Canada. Cleared at Bedwell Hbr where the Canadian CG actually came aboard and “searched” the boat, a Beneteau 35s5. I think they confiscated an apple. On to Montague Harbor to anchor for the night. As we entered we noticed where the boats had anchored so went over there. “Oh Christ! It’s 42 ft deep here!!“ I had never anchored in water that deep, and frankly, did not even know
if the Bene was properly equipped. So we reconnoitered along the shoreline where we discovered an area about 20 ft deep. But, the tide was supposed to drop 20 ft that night, low tide occurring near dawn.
Being from FL, having a whole foot under the keel over mud bottom was like home sweet home!! So we anchored in about 20-22 ft, the only boat over there. Next morning, the little tulies (as I called them) where lying at the surface; the Bene was tilted a few degrees. Clearly, we were aground. “What now, skipper?” “Let’s have breakfast!” By the time the dishes were stowed and we were ready to get underway, we were floating up-right.
No problema!
Fast forward to Southern CA. About the first thing I did to the Pearson, which we shipped here, was to put on 300 ft of 1/2” nylon rode with 30 ft of 3/8” chain, plus switch the bower to a 10 kg genuine Bruce from a Danforth. (The Bruce also rode much better on the roller.) Approximately 7:1 scope in 50 ft, about the average depth of Long Beach Harbor. About the shallowest I remember anchoring here (but there have been so many), not in a municipal Special Anchorage, is about 12-15 ft except for one time at Coches Prietos behind the reef there where it was about 8-12 ft (stern-tied to shore).
The deepest is 90 ft at the Isthmus in the Bavaria; a miserable night!!