NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Pilot charts
From: Gary LaPook
Date: 2008 Apr 16, 23:06 -0700
From: Gary LaPook
Date: 2008 Apr 16, 23:06 -0700
Gary LaPook writes: All of the roses on the chart are "wind roses" and should all be blue but there appears to be some problem with my scanner. The current arrows are green and are not associated with roses. gl On Apr 15, 11:11 pm, "Andres Ruiz"wrote: > Dear Gary, > Such strong currents no exist. 30 is not the speed, is the percentage of occurrence in current direction. > > Reading Current Roses: > Like the wind rose, the current rose graphically, (attached pic), depicts numerous current characteristics such as percentage occurrence of current in eight compass directions, and speed in knots of the current. The length of the 8 lines radiating out from the circle indicates the percent occurrence of current FLOWING TOWARDS each compass direction. The longer the line the higher the occurrence in that direction. If the length of the line exceeds the area available to display it (approximately 30 percent), the actual percentage is displayed. The number of feathers on the line indicates the speed in knots of the current in that direction with each feather representing 0.2 knots. > > -----Mensaje original----- > De: NavList@fer3.com [mailto:NavList@fer3.com] En nombre de Gary J. LaPook > Enviado el: mi�rcoles, 16 de abril de 2008 1:43 > Para: NavList@fer3.com > Asunto: [NavList 4842] Re: Pilot charts > > glap...@pacbell.net wrote: > > I have attached a portion of the January Pilot Chart of the South > Pacific Ocean published by the Defense Mapping Agency. Until I looked at > this chart I had no idea that currents in the South Pacific could be so > strong. The green arrows show the current direction and speed in knots. > For example, the current shown passing the southern end of New Zealand > is 10 to 20 knots! And in the Gilberts it shows up to 30 knots! How do > ships manage to maneuver against such strong currents? > > gl > > Current Rose.PNG > 1KViewDownload --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---