Back-up Depth Sounders?

Jun 25, 2004
479
Hunter 306 Pasadena MD
Michael, most of the time the concept of a good fleece to throw on, in the AM so you can sip a cup of coffee in the cockpit would be foreign. They also only know Orca from the movies or in google images.

We have so much wonderful water to explore it is sometimes overwhelming.
When we charted in the San Juans, I took the boat (a 44' Beneteau) over to Victoria BC. Rounding the point (under motor), I couldn't figure out why we were making just 2 knots. Later, I looked at the current/tide tables... Another huge difference between that area and the Chesapeake.

The difference between checking into Canada and back into the U.S. at that time (2010): the check-in at Victoria was, you walk to the end of the dock, pick up the phone and record a message that says "Hi. We're from the US in boat X, and here's the time/date". That's it. Coming back, we checked in with US CBP at Roche Harbor. They searched the whole boat, checked everyone's passports, and scanned our boat with a geiger counter. My brother in law set it off. (Recent nuclear stress test...) :)
 
Oct 10, 2019
114
Signet 20 0 Ithaca
I like the idea of casting ahead with a bobber and a weight. We have no electronics and rely on a good old fashioned lead line (and bad charts). The problem is, by definition we're only sounding the depth of the water we're in, not the water we're going to be in.
 
Jan 5, 2017
2,318
Beneteau First 38 Lyall Harbour Saturna Island
552BACAB-A6BF-4CF0-BD62-59F905F0F504.jpeg Here we are anchored in 12 fathoms. Not far from shore.
F44C9BB8-2AB1-48B5-BD81-37C234A4408A.jpeg Depth alongside here was over range for my depth sounder.(200’)
 
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dLj

.
Mar 23, 2017
3,794
Belliure 41 Back in the Chesapeake
I always carry a lead line. A depth sounder only gives you the depth where it's looking. I used to sail, and anchor, where there were a lot of uncharted rocks. I'd walk all along the boat making sure no rocks near, then take the dingy and scout around where I'd swing to be sure no rocks where I might end up. A hand held unit might be pretty cool, never owned one though.

dj
 
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Jul 27, 2011
5,102
Bavaria 38E Alamitos Bay
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 :yikes:. 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:doh: 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!!
 
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Jan 5, 2017
2,318
Beneteau First 38 Lyall Harbour Saturna Island
That can be a little scary Charlie. We have tides here up to 25 feet. 12/15 feet would be OK at low tide.
 
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Jan 1, 2006
7,364
Slickcraft 26 Sailfish
Different strokes ... In Peconic Bay 20 feet is relax time.
In Florida, on the Indian River Lagoon, we're lucky to have 7 feet. In the Intercoastal channel maybe a bit more - 'course the rest of the lagoon has to deal with the spoil areas.
 
Jan 5, 2017
2,318
Beneteau First 38 Lyall Harbour Saturna Island
Different strokes ... In Peconic Bay 20 feet is relax time.
In Florida, on the Indian River Lagoon, we're lucky to have 7 feet. In the Intercoastal channel maybe a bit more - 'course the rest of the lagoon has to deal with the spoil areas.
7 feet leaves me with 2 inches to spare ( if I’m not loaded down for cruising). What are the tides like there?
 
Oct 26, 2010
2,013
Hunter 40.5 Beaufort, SC
Looking at 8 to 10 foot tidal range here in southern South Carolina. Most of the shallow water around here is mud with some areas of sand or oyster beds with good depth in the Port Royal Sound but less so in the Saint Helena Sound and along the more restricted portions of the ICW Charted depth is pretty accurate.

I know it goes without saying but when using "bottom contour navigation" make sure you know the depth of your sonar transmitter below the water surface and account for that.
 
Jan 5, 2017
2,318
Beneteau First 38 Lyall Harbour Saturna Island
Normal tide range here, failing wind driven, is usually around a foot- Todays shows .3 foot- 3 or 4 inches, and one high, one low per day
It’s a little different here. On the south coast our larger tides are about 15 feet twice a day, as you go north the tides get bigger. Prince Rupert gets tides of 25 feet and as you get up into Alaska I understand some places have even larger tides. It makes you Leary about throwing out the hook without checking it twice.
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,105
CAL 35 Cruiser #21 moored EVERETT WA
What? Only twice?

What about the williwaws? You want to have enough scope for tide and wind.

With a 100 feet of chain and 250 of rode I sometimes wonder, is that enough.
 
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