Sailing without depth sounder?

[LouK]

If you’re familiar with the Chesapeake, then you’ll know that one could walk about 2/3’s of the way across it. There are plenty of places where the depth a mile out from shore is only a couple if feet deep. Also 7’-6” is considered by some fairly deep for the Chessie.

That said, with a decent chart plotter or app on an ipad, I’d probably go. Hopefully you either have a dingy to kedge off or BoatUS.

[CaptFrankM]

I may have missed it, but what part of the Chesapeake Bay are you planning on exploring? Some parts of the Bay (mostly the tributaries) haven't been surveyed by the USCG for over 60 years.

On the other hand, running aground in the Bay isn't usually life-threatening. Most of the Bay isn't fifty feet deep.

[Montanan]

One of my three sailboats [my lake boat] has a swing keel which I leave unpinned so that it can be quickly raised and so that I can navigate by sailing by Braille. The depth sounder no longer works, I had it installed primarily for locating fish, not for determining the bottom.

The steel keel lowers to about 6 feet draft when deployed and is hinged by a large through bolt. A second through bolt can be inserted to cause the keel to no longer be able to hinge and swing.

When I hit something with the forward edge of the 600 + pound swing keel it makes for a thud and a significant slowing of the boat as the keel has to pivot backwards and rise over the impediment. This touch and go scheme works particularly well when exploring shallows. Or when desiring to beach the boat for a lunch break, as I just head directly to shore and let it run up to a sliding halt on the rocks or sand below; such intentional beaching tends to scare newbees aboard and / or persons along the shoreline to see a sailing boat drive up hard onto the shore. I drop a stern anchor about 50 yards away from the shoreline and play out rode until the keel stops the boats forward travel towards the shoreline, I then have a line tied to a shore hardpoint from the bow and I pull the boat back a short distance from the shoreline by hauling in the rode to the anchor that I initially dropped.

The joy of having a swing keel for the lake boat is that the boat converts from 6 foot draft to 21 inches when it is raised. 21 inches allows for coming very close to the shoreline so as to be able to walk in. It also has a swing rudder which will also kick up or can be raised up. I can readily join the alongside the pontoon boats for socializing.

Both the swing keel and the swing rudder facilitate transporting the boat via a trailer and utilizing a boat ramp. I would never advocate such a system for my larger boating ocean trips where I do not desire to go exploring into such shallows.

The unpinned swing keel would definitely be a major hazard if the boat was to capsize as the steel keel would be pivoting and slamming about uncontrollably fore and aft, but then I don't capsize my lake boat when day or overnight cruising.

FYI: I do not have a Braille enabled navigational chart plotter connected to the Braille depth sensor.

[donradcliffe]

Having taken an 8 ft Beneteau around the world, if you haven't polished the bottom of the keel, you haven't calibrated the depth sounder. While the PO hit some ledges in Maine at 7 knots, we never hit anything hard in the Chesapeake. BTW the keel is still attached to the boat, just had to take a hammer and fairing to the lead a few times.

One rule for navigating skinny water--don't go faster than you can back off.

Know your tide levels when anchoring, and the tide datum for your charts. The water levels on the Chesapeake can also be affected by strong winds.

Sailing into skinny water is not recommended--we bounced of a reef above Cairns that was charted at 15 feet. We were trying to find an anchorage and should have dropped the sails. Fortunately the preventer did its job and broke when I crash gybed.

Enjoy your weekend.

[Grith]

The way we use our ultra shallow draft cruising yacht means I have two. One is a depth only with its sender mounted inside my hull rearward of my swing keel case.
( I would have mounted it further forward but we are water ballasted and these areas are double skinned.)
The other is a full fish finder sonar unit with side scan mounted on my transom.
Both readouts are on my wheel binnacle the standard depth unit with a low depth alarm set at 60 cms when we draw 30cms at minimum draft settings.
We spend a lot of time exploring beyond the areas charted for depth and my chart plotter regularly has me well aground!
These areas also often subject to strong tidal flows or inland waters settings and can have very poor water visibility as well.
My unweighted swing keel is my other alternative depth sounder and I leave it unrestrained and have my twin swing down rudders on sacrificial t cleats when running very shallow.
Photo shows a planned and regular occurrence dried out as an overnight anchorage in a high tidal area with both bow and stern anchors set to keep us landing in a known soft safe spot.

[jheyland]

I like the idea of getting something working - I used a sounder designed for the back of a motor boat setting it below the propeller shaft when my regular one broke in the Bahamas - it worked well enough.


That said, the charts for the Chesapeake are pretty good, you should not be 50' off anywhere (it's my cruising area and I haven't been that for off in quite a while).



The other good news is that the bottom in the Chesapeake is mostly very forgiving, softish mud. If you go slow if in doubt, you should be able to get yourself out of a grounding in most places.


Tides aren't big in the bay, wind often has more of an effect. Winds from the South tend to make the waters rise, an effect more pronounced the higher up you go.

[gonesail]

i wouldn't take a power boat out without a depth sounder .. much less a sailboat.

[MVDarlin]

Agtee in hull depth finder is a quick cost effective fix. Transducer $120. Get a gps/depth finder hhead unit. Good to have redundant system. I have 2 units on my 1980 34C&C. One transducer is under the fwd V berth. Another is just fwd if the engine.

[hugosalt]

Did a delivery from Long Island sound to Maine on a 34 fter with no depth finder.
Explained to the owner it wasn't necessary however one would be limited to well charted
areas (deeper/safer) and miss all those wonderful skinny hidy holes. Not to mention playing the lottery going into a changable shoal inlet. (New Jersey coast comes to mind)
Then as our electronics started to fail I explained how a depth finder could help confirm a position. (Think? my paper charts were the only ones on board)...
...While waiting on weather we purchased and installed a in hull depth finder.
Both owner and I were very happy as a lot of hard stuff up northern New England coast.

[Jweyndling]

Have you tried totally powering down your nmea network? I just had a similar issue on my boat and after turning off the main battery breaker for a few seconds, the network miraculously came back to life !

[thomm225]

You can download OpenCPN to an old computer with charts for the Chesapeake Bay in minutes. Afterward just connect your GPS and to OpenCPN/the computer and you are set.

OpenCPN has been almost exact as far as depth since I have been using it 2017.

I use it with my ancient Depth Finder when I am way up the creeks in the Bay where there are no longer channel markers.

OpenCPN depth where my boat shows up on the chart usually matches up with my depth finder so I can find a spot with 6' or more depth to anchor in.

Also watch the water when you are in near the shallows. The wind and wave action will usually tell you where the shallow water is.

[Kettlewell]

Sure, you can cruise temporarily without a depth sounder. Just be cautious where you go. Charts are pretty good with depths in major channels and harbors, but once you get off the beaten track up creeks and after the buoys end charted depths are only a suggestion. Luckily, the bottom in most of the Chesapeake is soft mud, and you can use the time-honored tradition of following someone else in. Believe it or not, before depth sounders boaters used a lead line to measure depths and I have done so when the depth sounder went out. Just rig up a rope with a weight on the end (maybe a big shackle) and some knots showing depths. Proceed slowly so that someone on the bow can drop the line over the side and give you occasional readings. You really only need it when the water gets shallow, and it's kinda fun to do things the old fashioned way.

[Don C L]

I know many folks know this but if the boat is moving, the lead line must be cast well forward of the boat and then read just as the line becomes vertical. Even if there are no knots or leather tabs on the line, 6 foot tall folks can do the old fashioned way of stretching the line from hand to hand to measure the 6 foot fathoms. And the genuine old lead weights have a cavity at the bottom for some wax to capture a sample of the bottom sediment. Butter and cream cheese work too in colder water

To make it work you have to be going no more than about 2 or 3 knots in about 15 to 20 feet deep. The deeper the water, the slower you have to go to get the readings.

[Notyetsinking]

Originally Posted by CaptFrankM

I may have missed it, but what part of the Chesapeake Bay are you planning on exploring? Some parts of the Bay (mostly the tributaries) haven't been surveyed by the USCG for over 60 years.

On the other hand, running aground in the Bay isn't usually life-threatening. Most of the Bay isn't fifty feet deep.

Ended up changing plans a bit due to the issue. We were initially planning on sailing to Cambridge, though now are headed to Annapolis. So the trip now is Baltimore (home harbor) -> Annapolis. Not ideal but given the circumstances wanted to be very conservative with the itinerary. Ended up buying a handheld depth sounder from Amazon just to be safe.

[Notyetsinking]

Originally Posted by Jweyndling

Have you tried totally powering down your nmea network? I just had a similar issue on my boat and after turning off the main battery breaker for a few seconds, the network miraculously came back to life !

I tried cycling it several times. My best guess is I somehow caused an internal short or something inside the Hercules computer when I pressed my voltmeter into the network. Though for some reason, only some of the 4/5 displays seem to have died . It is more of an annoyance as the system was in need of replacement; it is likely from 1995, and had a horrible habit of dying when I needed it most. It is amazing to me that I can buy industrial grade equipment with ratings for MTBF for significantly less than any (recreational) Marine alternative.