will the humminbird 565 show thermocline

Discussion in 'Fish Finder Review and Study' started by Montgomery, Dec 8, 2007.

  1. Montgomery

    Montgomery New Member

    Messages:
    257
    State:
    OHIO
    well i do beleive i want to go with this unit . but was wondering if it showed thermecline. isn't that important to know in the summer months. and i hope i'm not wrong here. cant you lower your bait down and see it on your finder. i heard once you coulf watch a jig at so many feet on some of these. what about the 565 ????? i want that feature and the thermocline thing. i fiqured , if i can just find depth , thermocline , and could see my bait . it has to improve my catching numbers..
     
  2. Mr.T

    Mr.T Active Member

    Messages:
    2,554
    State:
    MO
    Sonar units work primarily based on density changes - the sound emitted from the sonar reflects off of objects that are more dense than the surrounding water.

    The thermocline is just an abrupt change in water temperature as you go deeper. The density of water changes in relation to its temperature, and it's that sudden change in density that causes sonar sound waves to be reflected back to the unit and picked up. A fish or a log are both significantly different in density than the water and will reflect the sound waves in the same sort of way (though it's primarily the air bladder in fish that gives the strongest return - the density of the air in the bladder is just about as different from the density of water as you can get.)

    The bottom line is that any decent sonar unit, when properly adjusted for signal gain and noise rejection, should be able to detect and display the thermocline. Units with higher power and higher screen resolution will do a better job of displaying the thermocline.

    As far as seeing your jig bounce up and down, again, nearly any decent sonar unit should be able to show that, provided your bait is located so that the transducer signal will bounce off of it - usually, that means you'd need to be jigging straight below the transducer.

    However, neither feature that you've expressed an interest in is particularly useful for your day-to-day fishing. You'll spend very little time fishing directly beneath the boat, so you'll seldom be able to see your bait bouncing up and down. And the thermocline, while important for picking a good place to fish in the heat of summer, is not a specific feature of any unit, just a by-product of the way they work.

    I don't know what your price range is, but I'd recommend buying the unit with the most power and highest vertical screen resolution (in that order) that I could find. Color is nice but not necessary - I'd take a monochrome screen with more power if it was the same price.

    Typically, if you can afford a fairly recent-model Lowrance or Humminbird unit in the $300 to $500 range, you'll get good performance and a good set of features. Less than that and you're likely to be disappointed.

    I wouldn't get too caught up in the marketing hype either -- "dual beam", "quad beam" all that kind of stuff. Get a unit with a standard 20 degree single-beam transducer and you'll do fine. Again, focus your money on buying more power and higher screen resolution.
     

  3. Montgomery

    Montgomery New Member

    Messages:
    257
    State:
    OHIO
    man thank you ! i didn't expect such an informative answer. but it was greatly appreciated. thank you !