depth sounder vs fish finder

[Robert The Gray]

While responding to Ray Chang's post about transducer installation, I began to wonder why more sailors do not use fish finders as opposed to depth sounders. I find the traditional depth sounder to be strangely massive in the hole required and the depth of spaced used behind the display. The information that it gives is the same as a lead line without the capacity of determining the nature of the bottom. It does give a moment to moment readout but this will in no way help with avoiding collisions with rocks, it did not really help me stay off the mud up in the delta where the ground shoals gradually. I found that the fish finder was like an underwater radar, of course it is sonar but I am referring to the richness of the information received. The fish finder had several different sonar arrays. It would show bottom profile with good accuracy, with data from in front of the boat. When I was poking around the south end of Angel Island, just west of Point Blunt, and was amazed to see the underwater rocks loom up in the profile as I motored past. If I was making the decision to out fit another boat I would go with the fish finder instead of a depth sounder. I do not know of the power draw differences between the 2 but I imagine it is not that great.
A sail boat is an excellent nature observation platform, it was really fun to be transiting the deep waters of the bay and to see below the water as well as above. Very clearly on the finder you could see the herring schools in their spinning bait balls while there was no sign of them on the surface except for the waiting birds flying over head. Has any one else had fish finder experience?

r

[Ryan]

My opinions mimic yours, and have often asked the same question. I have also found the newer units with color displays are, with a little practice, excellent at helping determine bottom compositon for potential anchoring spots.

[Tim]

These days, with the new, small inexpensive and power-miserly displays that are readily available, there seem to be few reasons not to consider a fishfinder for a sailboat.

I wonder if the "bias" against them stems from the days, not so very long ago, where most fishfinders available were huge CRT boxes that just took up too much room and too much power to operate?

I used to use them back in the day when I had a powerboat They are handy, though it takes some time to really understand what the display is telling you.

This all makes me wonder why I don't have a fishfinder. Put that on the list of things to install on the next boat.

[Bluenose]

I am currently transitioning Bolero from no on-board power to having a small battery with a roll up solar panel. Primarily so I can have depth sounder input into the gps. The Garmin unit that I have also supports a fish finder transducer but what I found was that the power draw for the fish finder was quite a bit higher than for a depth transducer alone. May not be a real problem for boats with "real" electrical and charging systems.

To bad really as I was starting to get excited about having a fish finder.

Bill

[Henk]

Ahem, is that a little horizontal smudge on my monitor or did I just see a nine letter P word? No, it couldn't be... could it?

We use a Humminbird 150 fish finder on our sailboat...
And I don't even fish. But the nice thing about them is it shows bottom contours and with a bit of practice you can also make out the type of bottom; mud, sand or rocks can be distinguished. Helpful when anchoring. I think I paid about $100 and it shoots through the hull so installation was easy. It is very accurate (checked with lead line) and in good conditions gives readings to about 600 feet. I also use it to double/triple check my location on the chart.

[Triton 185]

I agree with the idea of having one on board. For years, I have used a fish finder for reading the bottom and depth. At the beginning it was to find the fish, but now I use it to determine depth and bottom conditions. I have noticed that it doesn't read well (or at all) when above a certains speed when in a speed boat, but that isn't an issue with a displacement hull.

[boatsnh]

4 years ago we installed a Navman color fishfinder to replace the old "spinner" depthsounder that came with the boat. It does provide some bottom definition & the kids love to look at the "fish". Worst case set it to "numeric" display & it looks like a standard depth sounder. Much better display for the $ than standard depthsounder - never an issue with it reading corrrectly while sailing.
Mike