Depth Sounder Setup options

[Seajet]

Interesting how flasher sounders are so popular as ice fish finders, check out the modern ones at Amazon.

http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=026VA8F1G1E543FKFN1R

I started fishing professionally with a Lowrance flasher and progressed though to heavy duty crt units, one I bought second-hand from a trawler cost the original buyer the equivalent of a decent house. Now retired I'm just updating the digital one on my yacht. I have had several failed attempts on EBay uk trying for a late version of a Seafarer but keep getting outbid by other people who obviously think like me.

fishermantwo,

how about the NASA depthsounder jobs ( Stingray ? ) which still use the whirling rotor technology; no idea if they have the same quality issues as some other nasa kit.

I did have a boat with a late model Seafarer echosounder ( 700 ? ) which had a small LCD display as well as power saving mode with shallow & deep alarm anchor watch mode; I'd quite fancy a system like that now, as long as it worked and stayed working !

I did like the easy gain control on the old sounders giving clear ideas of both seabed & hard undersurface to the user, in that respect I feel modern kit has taken a retrograde step.

 

[MudShipper]

Old Seafarer

Thanks again for all replies, and the varied opinions. For those who have asked, I have no immediate plans for the Seafarer (It is a 700). It still works after its own fashion, but in these shallow, rapidly changing depths on the East Coast, I find that having to constantly go down into the cabin and adjust the gain is a bit of a chore. The cockpit repeater tells me the last good reading (in feet) and has mislead me on occasion - 14 feet and I was hard into the mud!

 

[Dave_Seager]

No offset to worry about if you get ( or make) one of these:

It is tricky setting the offset to anything other that the overall depth of the water.

 

[Bodach na mara]

VicS,

I'm reliably informed that 'transom mount' fishfinder transducers can be bonded inside a grp hull, thus avoiding any need for holes in the hull.

Haven't tried it yet but it seems promising.

My transducer is "bonded" to the hull with a large blob of builder's silicone. I works perfectly.

Unlike my old rotating flasher sounder. It is a "Leisure Lines" model (which is probably a re-badged version of another model) and it is a bit like me:- reluctant to start and get up to speed.

 

[Poignard]

VicS,

being paranoid I have 2 sounders on my boat, one in the cockpit used for quick decisions and one in the saloon largely for anchor watch on shallow & deep alarms - at the time I fitted these a whole separate system was the same price as a repeater so I went for the redundancy of 2 separate systems & makes.

I thought of fitting two NASA Clipper echo-sounders (to give redundancy) but then it dawned on me that wouldn't work unless they operated at different frequencies. Presumably yours do, or maybe you don't run both at the same time?

 

[Stu Jackson]

Offsets: we use NONE or Neither.

I find it much simpler to have slowly run our boat aground on a soft mud bank and noticed the reading. It said 4.4 feet. Regardless of what the keel depth or distance below the waterline may be, I KNOW, absolutely, that if my depthsounder reads 4.4 or less I'll b aground. No maths needed.

I find mental arithmetic in shallow water to be a distraction. Knowing the absolute depth in varying tidal waters is not an absolute, either. And charts, as has been said many times, are only as good as the original or most recent survey anyway.

We have a lead line, too.

 

[Ruffles]

Mine was set with zero offset when I bought the boat and, like many people I bet, I'm too scared to change it in case I forget I've changed it!

We touch at 1.1m on a 1.5, draft.

Our greatest achievement so far is 0.6m.

 

[Ex-SolentBoy]

When we were out of the water I measured the distance from the transducer to the bottom of the hull.

Easy to set the offset. Ours reads 0 just as we hit the mud. I prefer it that way as the only tidal calculation I really worry about is the one about anchoring in enough water. One click on the plotter tells me how much it will drop from now to the next low. As long as I have that below the keel when we stop I am happy. Plus a bit extra of course. A little bit if it's mud, a big bit if it's rocky. ?

 

[Billjratt]

Vics, if you're going to fit a high intensity LED to the whirly, I think it may be an idea to fit a resistor and switch for use at night, or you may find yourself mesmerised by your own version of Ka!

And, (for the OP,) I set keel offset to actual depth under the boat in feet, only problem is my ST60 gives me tenths instead of inches just as the situation gets critical! (My home marina is silting up and sometimes it's touch and go)

 

[Chrissie]

I dried out yesterday and monitorred my depth as I went down, I wasnt sure what my clipper was set to. Most worrying, it read 1.4 m when I knew I was in 1.4m of water, but it still read that when I touched bottom, I have a draft of 1.2m, when I am sailing I can be in 0.5m in shallow water at times, which doesnt all add up.
Perhaps the gain threshold makes a bigger difference than I had expected.

 

[Billjratt]

The reading presented can depend on the quality of the bottom, firm stuff gives a nice healthy reflection, while gooey mud and weed is poorly defined.
It's one (another!) piece of information on the chart that I often forget to keep in mind, as I'm usually only concerned with jaggy bits.

 

[Seajet]

Parsifal,

I did indeed get conflict between the 2 sounders, the transducers were about 3' apart in front of the keel, in-hull.

The Navico seemed to have the say over the NASA Clipper, which sometimes froze if both were on at the same time.

As the Navico has now died, I'm fitting a Garmin 100 fishfinder, the transducer bonded to the relatively flat aft hull.

Chrissie,

Interesting you should mention '1.4', that's what the Clipper depth display in my cockpit always says when I get the impression things are getting shallow / minimal and it seems to suggest this ( default ?) figure in an effort to make out it isn't really confused !

 

[shaunksb]

Bear in mind...

Don't forget that the bottom shelves so for those who set to water under the keel there may not be the same water under the rudder. That also assumes the sounder is positioned by the keel.

To the OP, if you sail in shallow waters it must surely be easier to set to depth of water to make it easier to follow contours.

_________________

 

[MudShipper]

Post several replies to the various contributors, but seems a bit hit and miss which ones get through into the thread.

Thanks to all so far, some good points made. I've got some thinking to do about how I use the sounder for my sailing before installing the new one. Like many questions, there is no clear and definitive answer that covers all likely situations. As many have said, pick one and stick with it to avoid confusion.

 

[Bilgediver]

I use the offset to depth below the keel but I could see why you would set it to actual depth of water (making it easier when working out depths at states of tides). I can't see why you would leave it as depth below transducer, that seems a kind of odd halfway house to me. Would there be a benefit for depth below transducer?

No option with some of our clockwork Seafarers

 

[Stu Jackson]

Offsets: we use NONE or Neither.

I find it much simpler to have slowly run our boat aground on a soft mud bank and noticed the reading. It said 4.4 feet. Regardless of what the keel depth or distance below the waterline may be, I KNOW, absolutely, that if my depthsounder reads 4.4 or less I'll b aground. No maths needed.

To add to some of the more recent posts, I have a picture of our depthsounder at 2.8 feet!!!

We were tied up in a marina during springs on a mud bottom!!!