Sailing without depth sounder?

[Simi 60]

Originally Posted by Chotu

That doesn’t really happen in the continental United States. I think our charts are pretty good over here..

This person is asking about spending some time in the Chesapeake. Not navigating an atoll in the South Pacific. Lol. .

10 miles from a major Australian shipping port are the examples I was talking about.

[Jammer]

Originally Posted by Chotu

That doesn’t really happen in the continental United States. I think our charts are pretty good over here.

I have polished my keel in 30' charted depth in the continental U.S. of A. as recently as last spring and had a close call in 20' of charted depth two days ago.


I also went upriver without incident 2 miles past a USCG buoy bearing a lengthy screed about shoaling, flooding, and the fact that navigational hazards led to the USCG removing the channel markers for safety reasons (budget considerations, curiously, were not mentioned) -- something I would not have done without a sounder.

[Notyetsinking]

Originally Posted by JPA Cate

The only thing wrong with that is that they have to keep their eyes mostly on the chart plotter, which will take away from the quality of the watch they could otherwise be keeping. To me it is a serious flaw in the plan, but I still think that as long as the bottom is mainly gooey mud, and they stay away from the shallower bits, they'll probably be okay.

If they have kept their records of places safe to go stored in their GPS, they should be able to stay out of much trouble.

We hope they will.

Ann

Not quite, the system I've setup specifically alerts you if you're heading into trouble (according to the charts, that is) so I won't have to be looking at them too closely(in theory ). Our plans are likely to be more conservative as a result of this, and hopefully won't be too long before getting the situation resolved.

[Notyetsinking]

Originally Posted by JPA Cate

Well, we have never sailed without a depth sounder. Some friends of ours circumnavigated with just a VHF (bridge openings, communication with others) and a depth sounder. The depths help locate you on the chart. We have taken lead lines to sound prospective berth's depths, too. (our first Insatiable ran aground with the bow about 8 ft. from the dock.)

I understand Labor Day Weekend is coming up and you want to take advantage of it, so give it a go and see how you do. If you touch at very slow speeds*, not much will happen where it is only mud anyway: stone or coral reefs are a different proposition. If you run aground at normal speeds, someone may get hurt, from a fall, when you stop fast. As chotu suggested, don't go near the skinny bits.

* I would say less than 2 knots. Most of our serious exploration of waters you cannot see into has been around 1 kn. to 1.25. And we used a forward looking depth sounder to keep us off hidden rocks, reefs, etc.

Have a good holiday weekend, just be really attentive to depths; and known ranges in anchorages.

Don't know your draft, but people can use marked sticks for sounding, even their boathooks; or make up their own lead lines. You prefer to stay off the putty.

Ann

Draft is 7`10, with about 4ft ish of freeboard , which is why we are looking into handheld depth sounder. The forward scans are something we are very interested in; they seem to be invaluable tools for exploring new areas. How do you like yours?

[Notyetsinking]

Originally Posted by ggray

There are places on the Chesapeake Bay where the chartplotter is not accurate, or perhaps I should say, not current.

I could have run aground in "30 feet of water" just off the southeast tip of Tangier Island if I had blindly followed the chartplotter. Just found this note at this spot on Active Captain: "Reported LNM Week 45/2017: Shoaling to 5-6 feet MLW has been found in the vicinity of Tangier Sound Light in approximate position 37 47 06.4N, 75 58 23.2W along the 36 foot depth contour."

The bottom there is very deep and comes up very quickly. The contour lines almost run together.

You could cruise the Chesapeake w/o a depth sounder, but you would be more limited. And rather than a weighted string, I'd use a pole.

Hopefully we will get the depth sounder up and running before the end of the year; Tangier and the surrounding area has been of interest to us for quite a while as we have heard nothing but wonderful things. In the absence of functioning equipment, I imagine the area would be too risky for us to try, though such circumstance would be regrettable. For now, it remains on the bay bucket list.

[Jim Cate]

Good points on the tides, though I assume you mean low tide?

Well, likely not! Running aground at high water means no chance of floating off with the rising tide.

Anecdote: In 1983, on our first trip to Hawaii we failed to leave an anchorage in Kaneoe (sp?) bay in mid day as planned. Left late arvo instead with the obvious low sun angle and promptly ran onto a coral head shoal... at near high water on the highest tide of the year! It was so high that the unofficial marker on the shoal was submerged and thus not visible. Big adventure getting off, lesson learned (I hope). Not our finest hour!

So, if traveling "blind" in questionable waters, best done around mid tide, rising, IMO.

Jim

[Notyetsinking]

Originally Posted by Jim Cate

Well, likely not! Running aground at high water means no chance of floating off with the rising tide.

Anecdote: In 1983, on our first trip to Hawaii we failed to leave an anchorage in Kaneoe (sp?) bay in mid day as planned. Left late arvo instead with the obvious low sun angle and promptly ran onto a coral head shoal... at near high water on the highest tide of the year! It was so high that the unofficial marker on the shoal was submerged and thus not visible. Big adventure getting off, lesson learned (I hope). Not our finest hour!

So, if traveling "blind" in questionable waters, best done around mid tide, rising, IMO.

Jim

Yes, this makes sense, and I am glad it was brought up. I've gotten so comfortable trying to fit through an inlet or the like at high-tide (7ft-10in draft), that my assumption now is that charts are accurate. I never really thought about what would happen if we got stuck . Will certainly take your advice on traveling on mid-tide. How did you lot manage to get off, being stuck on the highest tide of the year?

[Jim Cate]

How did you lot manage to get off, being stuck on the highest tide of the year?

A combination of swimming out a kedge and winching, a tug from a larger cruising yacht and six large and enthusiastic Hawaiians from a passing sampan who jumped in and physically rocked/humped/pushed while the tow was pulling and I was grinding and motoring hard in reverse.

This after the local volunteer rescue boat got their tow line around their own prop and I had to jump in and cut it off. I suspect that we had struck perhaps a half hour before high and we got off perhaps an hour after high. Not our best day ever... but we survived to cruise anew. BTW, by the time we got off the marker had become visible due to the falling tide

Jim

PS this was in my Yankee 30, not one of our later cruising boats.

[Don C L]

Not a bad idea IMO.
I have a lead line, an old depth sounder that seems to work ok and a battery operated one I can hang off the side. I rarely use any of them. But then I am not in Maine or Chesapeake Bay, I draw only 4 feet and I know the area fairly well. In my area there are a few places where shallow rocks stick up from the bottom that I have to watch for. Charts and depth sounders don't catch those very well anyway. That said on my last trip I did use the sounder one time to doublecheck a new anchorage I went into. Nowadays with GPS that puts you within 16 feet (supposedly) of what you see on your chart plotter or app, things are fairly safe IMO. When I was a kid if I got within a half mile or so of where I was headed (with RDF and ded reckoning on a foggy day) I thought I was a genius!

[Tedd]

Originally Posted by Chotu

Tie a weight on the end of a string. When you are in shallow water or to check depth for anchor scope purposes you can just use the lead line.

"Mark twain!"

[Chotu]

Originally Posted by Tedd

"Mark twain!"

You know, it’s pretty interesting actually.

Even if my depth sounder was currently working, I would use the lead line.

There is usually quite a difference between say, the starboard bow of my boat and the port stern. The distance is pretty wide be between those spots and can be different within the swing of your anchor radius as well.


I like the lead line especially if I am putting my stern toward some shallow area.

I just stand on the steps back there and drop the lead line to make sure that it’s going to be deep enough for my rudders.

Much more accurate than a measurement 35 feet away in the other direction.

I really am a fan of the lead line. I like it.

[Tedd]

Originally Posted by Chotu

I like the lead line especially if I am putting my stern toward some shallow area.

Great idea, I should do that when I'm setting a stern anchor.

[Bill O]

I assume the hull on a Tripp 41 is cored. If there are parts of the hull not cored/solid glass, you could purchase another transducer and mount it on the interior.

[Chotu]

Originally Posted by Bill O

I assume the hull on a Tripp 41 is cored. If there are parts of the hull not cored/solid glass, you could purchase another transducer and mount it on the interior.

And in case we are going to arrive at the idea of scooping out the core, filling with epoxy, then sticking the sounder on there, that’s why mine doesn’t work. Lol

For some reason that technique did not work for me. I must have got an air bubble in there or done something wrong.

[wingssail]

I am a firm believer in depth sounders. I have a sailboat with 8' draft and I am often sailing in skinny water, and I mean "sailing" and I also mean "skinny" water.

When ever I am underway there are four depth sounders pinging away (different frequencies). The whales must be irritated or entertained by my passing.

Two (high and low frequency) are built into the Lowrance chart plotter, one is included in the B&G sailing instruments, and one is a stand-alone Standard Horizon unit. I carry a spare for the Standard Horizon DS21 because that is the one which has been on display in the cockpit for 40 years, and I rely on it and its alarm although the B&G one is growing on me.

Alarm? Yes I usually set the depth alarm on the Standard Horizon to a depth appropriate to the area where I am sailing. This is because I'm often looking away from the instruments and might not notice an unexpected decreasing depth.

Could I use the chart and GPS to know the depth? Maybe if I was motoring, slowly, I might could do that, but when I'm sailing, and I am USUALLY sailing, not sitting in a captain's chair behind the helm position and motoring, I am not continuously studying the chart. What is my practice however is to plot a course on the chart ahead of time, through what is expected to be safe water, and follow that course. It takes only a periodic glance at the chart plotter to see if I am on my course. But charts have been spectacularly wrong more times than I can remember.

Do I have a lead line? yes and I use it occasionally, often in the dingy, some times at a dock to see the depth at the bow or stern.

Many people navigate with far less depth sounding capability. In my view, they are taking an unnecessary chance. They can get away with it for many years, but that does not mean it is safe, it means they have been lucky.

Photo: my instruments showing two depth displays