Sonar Information

Discussion in 'LOCAL SOUTH CAROLINA TALK' started by Sunbird, Dec 8, 2009.

  1. Sunbird

    Sunbird New Member

    Messages:
    781
    State:
    Sandy Run,
    Here is the formula I use to determine the width of my cone on the bottom. Depending on your cone angle, mine is 30 degrees, it is posssible to determine the width at any depth. Here is the formula.............:eek:oooh:

    Tan a =x/h

    X=h x (Tan a)
    X=5' x Tan a (15 degrees)
    X=5' x 0.02679
    x=1.34'

    Now I know this looks real odd to us Yahoosmen:crazy: but, I have broken it down into 5' incriments to understand. The 15 degrees is because the formula works off of right angles. You must multiply your answer x2.
    Here is 5' incriments.
    At 5' bottom viewed width is 2.68'
    10' bottom viewed width is 5.4'
    15' bottom viewed width is 8'
    20' bottom viewed width is 10.7'
    25' bottom viewed width is 13.4'
    30' bottom viewed width is 16.1'
    35' bottom viewed width is 18.8'
    40' bottom viewed width is 21.4'
    45' bottom viewed width is 24.1'
    50' bottom viewed width is 26.8'

    I am often asked this exact question so I thought I would figure it up for those who wanted to know.

    Now that's BIG STUFF!!!:smile2:
     
  2. Bill in SC

    Bill in SC New Member

    Messages:
    4,451
    State:
    South Caro
    Hmmm. I thought I remember a BOC member saying that the general rule of thumb was, with a 30 degree cone, a general width was basically the same as the depth reading. In other words, 25 feet deep would equal APPROXIMATELY a 25 foot width scan. I ain't too keen on math. So, are you saying to multiply your final answers by two, or are the figures you posted the final answers? If the answers you quoted were multiplied by two, then that would fall just about in the range that I was quoted here on the BOC.
    If your answers are correct as posted, then the actual scan is approximately half the depth reading. Please clarify.

    BB in SC
     
    Last edited: Dec 8, 2009

  3. catwhisper

    catwhisper New Member

    Messages:
    456
    State:
    georgia
    so at 50 ft a 26.8 ft diameter times two correct?
     
  4. Bill in SC

    Bill in SC New Member

    Messages:
    4,451
    State:
    South Caro
    That is what I want to know too.
     
  5. Sunbird

    Sunbird New Member

    Messages:
    781
    State:
    Sandy Run,
    Mama Sunbird took it to one of her Physicist today to make sure the formula and calculations were correct, He agreed. I will get her to run it by a different Dr. tomorrow to make sure. The figures are correct as listed. The actual width is approx. HALF the depth.
     
  6. Sunbird

    Sunbird New Member

    Messages:
    781
    State:
    Sandy Run,
    Remember the formula works off of right angles only. Look at the original equation. It is 15 degrees; half of 30.
     
  7. catfishinsc

    catfishinsc New Member

    Messages:
    507
    State:
    SC
    I didn't check them all, but the 5 ft is right. The rest look to be in line. In order for the diameter of the cone at depth to have the same diameter as the depth it would have to be a 53.13 degree cone.
     
  8. Bill in SC

    Bill in SC New Member

    Messages:
    4,451
    State:
    South Caro
    Cool, good info.

    BB in SC
     
  9. nanny patrol

    nanny patrol Member

    Messages:
    389
    State:
    SC
    Now thats useful info. Thanks
     
  10. BigBird

    BigBird New Member

    Messages:
    2,104
    State:
    Charlotte, NC
    dang all this math is getting me all excited.:tounge_out:

    What would the depth be in 15' of water with a waffle cone?:crazy:
     
  11. Bill in SC

    Bill in SC New Member

    Messages:
    4,451
    State:
    South Caro
    Depends on which end of the waffle cone is pointed downward! :smile2::wink::smile2:

    Bill in SC
     
  12. BigBird

    BigBird New Member

    Messages:
    2,104
    State:
    Charlotte, NC
    Thats Big Stuff Math right there!
    I would check your math but not going back to look up tangents....lol!:eek:oooh:
     
  13. striper steve

    striper steve New Member

    Messages:
    50
    State:
    south carolina
    impressive math but according to the lowrance website the answers may not be right. it gets kinda complicated but according to them a 20deg angle may show up to 60deg because of the way manufactures measure the angle. if you go to the lowrance site and look under sonar tutorial it explains it alot better than i can. ive been told that with a 20deg you see aproximately 1/3 depth(just what ive been told) but apparently thats incorrect as well.
     
  14. Sunbird

    Sunbird New Member

    Messages:
    781
    State:
    Sandy Run,
    I know what Lowrance says and if they have 'secret' technology working to enhance the coverage zone then what they say is true. I have merely taken the equation for determining the coverage at certain depths and worked them out. I have figured up the coverage numbers for a 20 degree cone also.
    5' it's 1.76'
    10' it's 3.52'
    15' it's 5.28'
    20' it's 7.05'
    25' it's 8.82'
    30' it's 10.58'
    35' it's 12.34'

    There may infact be funtions of the cone angle that, can and are, manipulated by Lowrance to enhance coverage. I don't know. I just thought it useful information for the Yahoosmen!!:wink:
     
  15. screamnclickersc

    screamnclickersc New Member

    Messages:
    755
    State:
    S.C.
    Sunbird you got too much spare time:wink:
     
  16. skiff1

    skiff1 New Member

    Messages:
    210
    State:
    south caro
    Its pretty confusing but it seems like you don't cover much area.
     
  17. nevets91

    nevets91 New Member

    Messages:
    604
    State:
    rock hill south carolina
    how did you even come across that formula. thats pretty interesting though i started doin the formulas to work for mine(20 degree cone) but then realized you did it already.ill have to remember that info
     
  18. gotta go

    gotta go New Member

    Messages:
    2,395
    State:
    SC
    I really don't worry about it cause all them blame thangs tell you lies. I had fish all under the boat and didn't get a bite but i was out there drifting and it wasn't showing up one single fish and i caught a 50lb flathead, same thing at wateree, no fish on fishfinder and i caught fish.:smile2: soo all this formula stuff is just to get you to think they know what they are talking about to get you to buy one just cause your friends have got one.:eek:oooh:
     
  19. katman#1

    katman#1 New Member

    Messages:
    1,209
    State:
    South Carolina
    thanks sunbird for the useful post
     
  20. slojam

    slojam New Member

    Messages:
    181
    State:
    scarolina
    useful&correct mathmatically.i have a lowrance i need to install&put to use. maybe someone will try to validate the 60 degree claim by lowrance.(hopefully it's true) lot of difference between 20&60 degrees.thanks again:)