Great Circle Distance Calculator
Swell Arrival Calculator
Use this tool to calculate the Great Circle distance
between any two points on the planet (in nautical miles) or to determine how
long it will take a swell to travel to your beach. See instructions further
down this page.
To use this tool just enter the:
Coordinates of your beach (or any destination/buoy).
The time the storm is first forecast (or actually
started) to produce seas aimed at your location (Assumes "local time"
unless you set your PC to GMT/UTC). (1)
The coordinates of the center of the fetch area
aimed at your destination from your favorite wave model (or a starting point).
The maximum sea heights that were forecast or
confirmed and that were aimed at your location. (1)
Enter additional storm positions and sea heights
(in 12 hour intervals). (1)
Click on "Calculate Swell Arrival Time"
or "Calculate Distance".
The results display in a new window. Swell Arrival
times are calculated for each swell period that should result (i.e. 17 sec
period swells will start arriving at XXXX, followed by 14 sec period swells
at XXXX, followed by 13 sec ....). Arrival time are calculated for each 12
hour interval, so results require some interpretation skill. Read the HELP section for more info.
(1) - These fields are not required when calculating Great Circle
- Use the tab key to jump quickly between
fields and the arrow keys to increment values in drop down boxes.
- Requires Internet Explorer 5.0 or Netscape 4.0 or higher. If using
Internet Explorer, Microsoft virtual machine (VM) must be installed for calendar/time
functions to operate accurately. (See HELP).