TRANSDUCER MOUNTING (SEE ALSO INSTRUCTIONS SUPPLIED WITH TRANDUCER) The most important and time-consuming part of installing a  depthfinder  is  determining  the  best  place  to  install  the transducer.    The  transducer  must  be  submerged  at  all times,  free  of  water  turbulence  and  air  bubbles,  and  its face  must  be  as  parallel  to  the  surface  of  the  water  as possible. Because  there  are  about  as  many  different  hull  shapes as   there   are   boat   models,   no   "best"   location   can   be recommended.  Trial and error testing may be necessary before  you  are  satisfied.    Of  course,  the  experience  of dealers  and  fellow  boatsmen  with  similar  hulls  can  be helpful. TRANSOM MOUNT This is the most popular transducer mounting for smaller boats as well as some larger ones.  Installation is quick and  easy  when  a  specially  designed  transom  mounting bracket  and  transducer  is  used.    It  permits  transducer removal    while    the    boat    is    in    the    water.        Equally important, it locates the transducer where it is safe from the  serious  damage  that  can  occur  during  beaching  or loading   on   a   trailer.      However,   putting   it   close   to   an outboard or I/O may cause electrical or sonic interference problems.  As a rule of thumb, try to mount the  transducer  a  minimum  of  12  inches  from  the  engine and as close to flush with the hull bottom as possible in a location that will be submerged at all times. INSIDE-THE-HULL This  is  an  easy  way  of  installing  a  depth-sounder  mid- season while the boat is in the water, but cautions must be  observed.    The  technique  is  popular  among  owners of  fiberglass  racing  sailboats,  and  certainly  can  be  used on  the  right  type  of  powerboat  hull.    The  fiberglass  hull must  be  solid  fiberglass  and  resin  at  the  "water  box" location,  without  any  core  or  air  chambers  to  interrupt the   pulses   intended   to   pass   thru   the   hull.      Primary advantages   are   that   no   hole   thru   the   hull   is   needed, there is no external unit to offer resistance to the flow of water  (no  matter  how  small),  and  the  transducer  cannot become    fouled.        Major    disadvantage    is    that    the maximum   depth   readings   of   the   depthfinder   will   be somewhat  reduced.    Pulses  cannot  pass  out  and  back thru  the  fiberglass  without  losing  part  of  their  energy. This  clearly  means  that  the  depthfinder  will  not  read  as great  a  depth  of  water.    It  is  impossible  to  make  any hard-and-fast  rules...    particularly  since  loss  increases with  thickness  of  fiberglass...    but  expect  that  ability  to read depths will be reduced 10 to 30%. Caution: Your Aqua-Probe depthfinder is sufficiently powerful    for    this    type    of    installation,    and    will generally  read  at  least  to  its  depth  scale.    However, there  are  a  great  many  depthfinders  on  the  market with   considerably   lower   transmitter   power,   and  a "water box" installation is not likely to be successful with them.  Some boats have a bilge pump sump or wet location that may serve as a water box. Transducers also can be cemented inside a hull using a 2  part  epoxy  resin.    Because  of  the  ease  of  installation, this is an increasingly popular technique and, due to the Aqua  Probe's  extremely  high  transmit  power,  will  work better    than    most    other    high    quality    units    available. However,   the   ability   to   adjust   for   optimum   distance between the bottom of the transducer and the inside hull is    limited.        Therefore,    success    can    vary    from    an installation   equal   to   a   "water   box"   to   somewhat   less efficient. In selecting a location for mounting the transducer inside the  hull,  find  an  accessible  spot  in  an  area  that  is  as level  as  practical  (since  the  "window"  or  bottom  of  the transducer should be mounted parallel to the water line) and   in   a   location   where   the   minimum   amount   of   hull vibrations     or     noise     might     be     transmitted     to     the transducer.  It is good to avoid a location close to engine mounts,  shaft  logs,  or  struts,  and  naturally,  any  place where the hull will be out of water when your boat is 19