*THE HULL TRUTH is the world's largest FREE network for the discussion of Boating & Fishing. Whether you're researching a new boat, or are a seasoned Captain, you'll find The Hull Truth Boating & Fishing Message Forum contains a wealth of information from Boaters and Sportfishermen around the world.
Welcome to the updated THT!
If you are having trouble signing in, please email feedback@thehulltruth.com with your username and we will help you. We thank you for your patience as we help you access the new site!
Random Quote: The short way is often the long way!
I own an old Chromoscope Color Depth Sounder,
It is in great shape as it is kept in a e- box.
I have purchased the boat this year and when I went to the Canyon on the first trip I realized at 500', the bottom breaks up and dissapears, then reappears as I come up the edge, back inot 500' of water.
Is it because of the transducer no being strong enough and can I add a bigger or better transducer in the winter, so I am ready for the spring??
Thanks
What sort of answer is that? Well, it could be your transducer is not of a design best matched to deep water performance and it could be that the mounting of your transducer is not such that it promotes optimum operation in deep water. Either of these two things could be the case, but neither is likely.
I have never heard of your fish finder and in fact don't even know if you are talking about a make or a model. One thing I do suspect is that no matter who made it or what model it is that it doesn't have more than about 250 watts of output power, maybe not even that much. Of course its also possilbe that it has gobs and gobs of power, but that its pulse repition rate has as a top limit to its duration of 0.25 seconds or maybe just slightly longer thant that. If its a queston of power then your depth will fade out as your drop over the edge. If its a matter of pulse repitition rate being limited to a quarter of a second then it will quit reading abruptly at a very consistant depth (it will vary somewhat because of salinity of the water and water temperature).
The solution in either case is a new unit, not replacement of the transducer. Besides that, I doubt that you could find a replacement for the transducer to tell the truth. That means that if you want to see deeper than 500 feet you may need to be considering a new bottom machine.
If you put a lot of time in out there in deep water you probably want at least 600 watts and a Kilowatt or more would be a good choice as well. There are other concerns too of course and choice of the appropriate transducer, particularly for folks who have quite specialized requirements. I've come to see it as unfortunate that most small boat fish finders are sold with some sort of standard transducer in the box. You might have a choice between mounting styles, but they are all really the same. It is just one of the little things I like about how Furuno sells their units. You buy the display unit that fits your needs, but then they give you a list of available transducers, a very large list indeed.
I should quit before I start really ramebling ....
I was planning on getting a brand new unit this fall anyway, but I was thinking of keeping this as a 2nd back up, ANd thought that if I just got a new transducer that would solve the problem, but probably not.
The unit is older and is in good shape and reads very well up to 500', so I may just keep it mounted and add a new 2nd unit and yes probably Furnuno.
All of my electrinics on my old boat were Furuno and never failed me.
Ps. Do you know of any Boat electricians that want to make some money this winter???
I am really considering re-wiring the boat. I know it is a big job, but It really should be done (1973 and years of neglect)
little debbie,
What area are you located in? If you are close to Wilmington NC, I have had Chris Powers do several things for me and his work is first class. I do not have his number with me, but will be glad to get it for you.
jim
Its on a 36 Hatteras, I'm going to assume its a big thru-hull puck. Have you checked the transducer for sea growth. Is it dual freq? and you are on low range 50?
Product Engineer, SMITH Marine Products, 21 Seacat, 2500HD Duramax/Allison
seacatrdier,
i also have that prob with my furuno fcv 667 (300 watts with a transom mount transducer). i can read down to 550' but i can't ever get past that. they advertise that the finder has a range of 1000' but i haven't ever come close. i'm fishing off of a seacat 25. the furuno dealer didn't know why that would happen except that maybe the cat produced a lot of dirty water underneath deterring the unit from working as well as it should. do you have any probs with this on your boat? how and where did you mount the transducer?
YnR, The problem as I see it with tiny cat transoms is you have no choice but to mount a tramsom transducer in behind the prop where it is subjected to turbulent water and general engine vibration noise interference. I got the best transom mount performance with the puck mounted really low 1/2" below the hull on the inboard edge and 2" below on the outboard edge.
But I gave up on transom mounting last year. Using Thom's technique, I mounted my new Sitex 106L's big dual freq thru hull transducer as a shoot thru hull. Its about 3 feet forward of the transom right on the keel line of the starboard hull. It works near about perfectly there at all speeds. That said, since I installed it I have yet to get out beyond the North Carolina shelf into water over 300'. But I have lots of gain left so I'm hoping it will not do the 550 drop out.
Another issue is the transducer itself. According to AIRMAR's web site, many of the standard transducers that come with many brands of sonar are rated for less power than the advertized rating of the bottom machine. Hummm. I find it curious that many brands of sonar are sold with a transducer rated for far fewer watts than the unit claims to have. Seems like putting a 40 watt bulb in a 100 watt fixture only gives 40 watts of light right??? Scan down AIRMARS offerings and for more money you can get high watt rated transducers. Now this is just my opinion, my theory is untested, but I how can any sonar unit perform better than the capacity of the transducer?
Product Engineer, SMITH Marine Products, 21 Seacat, 2500HD Duramax/Allison
Depth sounder stops reading at 500' ? 
