Seafarer Depth Finder

[tgalea]

We have an old Seafarer Depth Finder on our boat and we're quite unsure if this is working properly; i.e giving good readings. Any suggestions how we could check it out.

Moreover if there are any of you that have used this old tool in the past any suggestions to the use of the x 1 and x 6 knob and sensitivity knob ?

Any help would be appreciated

Cheers & Thanks

TYrone Galea.

 

[DanTribe]

Hello
You could check your sounder against a lead line or in a place of known depth.
I do not think that it is possible to adjust for offset, therefore the depth will always be measured from below the transducer.This is not a problem as long as you remember.The Seafarer came in either Feet & Fathoms[6feet] or Metric versions.
Using the x1 setting gives good accuracy at shallower depths, the x6 is for deeper water but the frequency of pulses is slower.Set the gain down until you get a clear single signal, too high and you get a multiple reading.
If you need to replace the transducer, the ones sold for Nasa sounders work well.
Somewhere I have an instruction book, which I will try to find.

 

[AndrewB]

Check the depth indicator against a lead-line (a piece of string with a weight at the end, lowered to the bottom when the yacht is at rest).

This check is highly important with any 'new' depth sounder. Check at several depths, say 10ft, 20ft, 30ft, and if necessary draw up a "deviation" curve. Also, run the yacht very gently aground (rising tide preferred!) and see what the depth sounder reads at that point.

The 1 and 6 refer to measurements in feet or fathoms respectively. (1 fathom = 6 feet). The fathoms measure is useful for navigation (or it was before GPS and with pre-metric charts); the feet measure is for shallow-water pilotage.

PS Beware the dial going right the way around, specially when set on 1. I panicked several times thinking I was suddenly in 4ft of water when actually in 64ft - or when I got a 'double-echo' from 32ft. The sounder won't work out of water.

 

[bedouin]

I've always wondered why Seafarer chose to have a x6 scale! In fact they retained the x6 multiplier even after they went over to measuring the depth in metres, but put two scales on the dial (one outside, one inside).

In practice I rarely used anything but the x1 scale (up to 20 metres). The only problem is that the shallow water alarm would go off in (say) 21 metres of water since it was not able to distinguish that from 1 metre

 

[tgalea]

Many thanks. Appreicate your help. Will do as you suggest.

Cheers.

 

[rogerm]

This is at a slight tangent.. I think the unit you are describing is the unit with a round face and a flashing neon or LED. This was a very basic unit and only has the knobs you describe.

Anyway my reason for replying is that someone gave me an add-on depth alarm for the type of unit I describe. It has a small head part that clamps on to the edge of the display and you position it at whatever depth is of interest. It connects to a smallish plastic box containing an alarm sounder and a battery.

It is of no use to me as I don't have that type of depth sounder. If it is of any use to you (or anyone else for that matter) they are welcome to it for the cost of the postage.
Roger