SUROB  REPORTS SUROBs are first passed to the Commander of the Amphibious  Task  Force  (CATF),  who  normally remains on board the task force command and control ship. Reports are also forwarded to the command ship weather   office   and   to   the   Naval   Meteorology   and Oceanography  Command  Center,  facility,  or detachment   assigned   forecast   responsibility   for   the exercise   or   operation.   These   responsibilities   are assigned in the weather support annex of the operation order. SUROBs are normally passed via voice radio from the beach to the command ship. In a few situations, a copy of the SUROB worksheet may be passed directly to  the  CATF,  or  passed  via  light  signal  or  flag semaphore. Before  and  during  actual  assault conditions,   communications   are   heavily   overloaded with  critical  command  and  control  traffic  and  tactical traffic. Although the SUROB is equally as critical to the success of the operation, the message should be kept as brief   as   possible. In  some  cases,  SUROBs  are sometimes passed using the SUROB Brevity code. SUROB  BREVITY CODE The  SUROB  Brevity  code  is  a  standardized  method of  encoding  and  transmitting  surf  observations  by  voice or flashing light when speed is essential. The Brevity code  uses  only  letters  to  pass  information.  When passing  these  messages  via  voice  radio,  each  letter  is pronounced  using  the  phonetic  alphabet  that  you learned  in  the  Basic  Military  Requirements  (BMR) course. The message is passed as tactical traffic to the weather  office  aboard  the  command  ship.  Normally, the Brevity code is decoded by the weather office and forwarded  to  users  in  the  task  group  in  the  standard SUROB  report  format.  Only  SUROB  observers  and personnel in the command ship weather office need to be familiar with the SUROB Brevity code. The   complete   observation   might   appear   as: WSKCC   SUGGY   ILELC   JYBXC   AW .   The identifying features of the Brevity code are the first two letters, which are always WS, and the arrangement in a few  groups  of  five  letters.  Complete  instructions  for encoding  and  decoding  a  message  using  the  SUROB B r e v i t y   c o d e   a r e   c o n t a i n e d   i n   C O M N A V - SURFLANTINST/COMNAVSURFPACINST 3840.1, Joint Surf Manual. In  the  following  text,  we  discuss  the  influence  of tides on surf and some of the sources for obtaining tidal data. Q26. Q27. Q28. REVIEW  QUESTIONS How can surf conditions be estimated at night? Who  are  the  primary  users  of  SUROB information? What is the purpose of the SUROB Brevity code? TIDES LEARNING  OBJECTIVES:  Recognize  how tides   influence   surf.   Identify   the   various methods for obtaining tidal data. Tidal influences have little effect on the height of breakers but can have a profound effect on the width and character of the surf zone, the strength of rip currents, and  sediment  transport.    As  the  water  level  rises  and falls  due  to  the  daily  change  in  tides,  the  water  flow creates currents. These currents flow toward the shore as a flood current with the rising tide and away from the shore as an ebb current with a falling tide. TIDAL EFFECTS IN THE SURF ZONE During a tidal cycle, the position of the surf zone is shifted  with  the  tide  both  vertically  and  horizontally, causing  the  intertidal  beach  profile  to  be  slightly  altered every 12 hours. In rip current systems, rips are strongest at  low  tide,  when  the  water  is  sufficiently  shallow  to concentrate   the   flow   of   the   current   within   the   rip channels. Maximum rip current velocities occur during the falling tide, and on most beaches, rips become better developed  when  the  tide  is  falling  or  low.  Offshore bottom  flow  also  increases  during  the  falling  tide.  In addition,  an  increase  in  tidal  range  will  result  in  an increase in sediment transport. This has a tendency to reduce beach gradients. Normally,  the  surf  zone  will  be  wider  at  low  tide than  at  high  tide,  given  the  same  size  waves.  This  is because the water level is lower and waves will begin to interact with the bottom farther from shore and break earlier. This wider surf zone can make the transit to the beach more difficult, and may cause equipment damage and troop fatigue. Also, sandbars and other obstacles, which  have  sufficient  clearance  at  high  tide,  may  be 4-15