Absolutely. It measures the distance between happiness and catastrophe. Having lived through going up the Irish Sea with about 25m visibility and before GPS - the Decca had gone on the blink - it was all that was left. I have two, an old one at the chart table and a modern digital one in the cockpit which I use mainly for anchoring. With two I can cross check for accuracy. I also have two leadlines. The obligatory one and a lighter one that covers 90% of requirements eg for sounding all round the boat when you lay up against a drying wall which you don't know.
I do use mine.
I set the shallow alarm so I can tack inshore without paying too much attention and it tells me when I am dragging through silt when running late getting back up the Wareham channel.
I am going to put my two pennyworth in and say that an echo sounder is essential. How many people have I seen who claim that they know exactly where they are and the echo sounder tells them they can't be there? Its the one bit of kit that doesn't really lie. GPS can be out - but the echo sounder tells you that you still in the channel. Tacking up a river like some other forumite, I tack on the sounding. We'll tack when we get to the 5 metre contour. (When racing more like - we'll tack when we've got 0.5 m under the keel...)
In the west country, life would be very boring if we had to sail within the bouyed channels all the time. I usually try to stay outside the bouyed channels - and for that, I watch the echo sounder. No choice for me....
How are you going to explore all the creeks and rivers that aren't bouyed?
In the Sjaelland Rundt race in one narrow shallow channel through the sand, upwind at night, its recommended to tack when the echo sounder reads 10 cms.. eeek
Nobody seems to have thought of a "lead line"? This is an essential piece of equipment for all yachts. What happens if you lose all power?
Not having an echosounder makes for a much more relaxing cruise. Before you set off make a good check of the tides to ensure you will not hit rocks etc then forget about depth until you come in towards shallower mooring areas. Using the lead line then ensures you travel at a safe speed and concentrate on whats going on outside rather than being transfixed on the echosounder.
Try it for a while I can guarantee a more relaxed cruise. /forums/images/graemlins/smirk.gif
Even when I am out pottering in familiar waters, I keep a weather eye on the echo sounder - its one more bit of information that confirms I am where I think I am. Its very nearly infallible and it very rarely goes wrong. Why go without it?