FastSeas is a weather routing and passage planning tool. It will calculate the fastest route to take you from point A to point B given the current NOAA GFS weather forecast , current oceanic currents , the performance of your vessel, and your comfort criteria.
Feel free to look around, but before you can actually run routing calculations, you'll need to log in. Logging in allows FastSeas to remember your polar and comfort criteria. You can log in using various social login options. I have taken this approach rather than having you register with a username and password because it's less work for me and safer for you - as I don't have to deal with passwords. There is nothing nefarious going on here. FastSeas is not going to be reading your posts or creating posts or any such thing.
You need to teach FastSeas about the performance of your vessel. You do that using the Vessel Performance tab. You only have to setup these performance settings once. FastSeas will save these settings and use them next time you come back. There are instructions on the Vessel Performance tab, so I won't repeat them here. The amount of data you have to enter on the Vessel Performance tab can look intimidating, but it goes pretty quickly.
Before FastSeas can calculate a route, you need to tell it where you are starting from and what your destination is. You do that using the Routing tab. On the Routing tab, you'll see a map with an "S" marker and a "F" marker. These represent your start and finish points. They can be positioned by dragging them on the map. Or if you prefer, you can enter the Lat & Long into the fields.
You can now run weather routing calculations by clicking the Calculate Route button on the Routing tab. After the calculation is complete, the route will be displayed on the map. You can also look at the details of the route on the Route Positions tab, and summary stats on the Passage Stats tab.
You can specify your comfort criteria on the Routing tab. You can enter the maximum wind speed in knots that you are willing to tolerate beating (forward of the beam), reaching (aft of the beam), and maximum gust conditions.
Note that you can run multiple calculations, perhaps with different departure times, comfort criteria, or destinations, and have all of these routes displayed in the same map.
You can also get routing and departure planning solutions from FastSeas via email (e.g. Iridium GO!, Sailmail, Winlink, and other email services) and via Garmin/DeLorme inReach devices. This is particularly useful when offshore or in remote anchorages - when you don't have access to high-speed internet. Results are provided by an automated email responder, which automatically calculates the route or departure planning result in response to your emailed request, and sends the result back to you in a reply email within a few seconds. Using the email responder service requires a FastSeas subscription.
To request a route using the email responder service, send an email like the one below:
To: email@example.com Subject: Bonaire-Porlamar SEND ROUTE: 12.0N, 68.3W, 10.9N, 63.8W
are the coordinates of your departure point (in decimal degrees) and
are the coordinates of your destination. The subject is not consequential - you can make it whatever you like. You can also specify coordinates
in degrees and minutes if you prefer as shown below:
To: firstname.lastname@example.org Subject: Bonaire-Porlamar SEND ROUTE: 12-0N, 68-18W, 10-54N, 63-48W
is 12 degrees 0 minutes North, and
is 68 degrees 18 minutes West.
A few minutes after sending your email, the automated email responder will send you a reply containing a Google Earth KMZ file which contains your routing solution. Each of the pushpins in the solution can be double-clicked to see the routing details at that point of the passage.
If you prefer to get a GPX file instead of the standard KMZ response, add a
switch to your request as shown below:
To: email@example.com Subject: Bonaire-Porlamar SEND ROUTE: 12.0N, 68.3W, 10.9N, 63.8W, GPX
The automated email responder will respond to the email address you registered with, or to any email account you setup in the Account tab - where you can authorize your Winlink, Sailmail, and Iridium email addresses. The KMZ file is typically very small (2-3 KB) and therefore very suitable for low bandwidth HF or satellite acccess. GPX files are larger.
If you would like to receive a compressed GPX file (zipped), then use a
If you would like to limit the number of days included in the route mailed back to you, then add a
switch, substituting the number of days you wish to receive:
To: firstname.lastname@example.org Subject: Bonaire-Porlamar SEND ROUTE: 12.0N, 68.3W, 10.9N, 63.8W, GPXZIP, DAYS=2
The default departure time for routing request submitted via the email responder in "now." You can adjust the departure time using the optional
parameter. For example, use
to set the departure time to two hours from now; or use
to set the departure time to this time tomorrow (24 hours from now).
You can optionally include parameters to adjust your comfort criteria. To set the maximum wind you are willing to tolerate forward of the beam,
(e.g. 20 kn). Use
to set the maximum wind you are willing to tolerate aft of the beam. Use
to set the maximum wind gust you are willing to tolerate.
If you would like to disable ocean current effects in the routing calculation, add a
switch to your request.
You can also optionally include parameters to adjust your polar performance and motoring criteria. To set the polar performance adjustment, use
(e.g. 90%). Use
(e.g. 3 kn) to set the boat speed at which you will start motoring. Use
(e.g. 7 kn) to set the speed at which you motor.
You can also get departure planning results from FastSeas via email. To get departure planning results, send an email like the following:
To: email@example.com Subject: Bonaire-Porlamar SEND DEPARTURE: 12.0N, 68.3W, 10.9N, 63.8W
The FastSeas email responder also supports Garmin/DeLorme inReach devices. Messages to inReach devices are limited to 160 characters of plain text - and so this imposes some limitations on what FastSeas can send.
InReach devices automatically provide your current location in all messages sent from the device, so there is no need to provide your current/start position latitude and longitude when submitting routing and departure planning requests from your inReach device. In you wish to specify a departure position different from the position automatically reported by you inReach device, then you certainly may include both departure and destination positions in your request.
When sending a request from an inReach device, you must include the
Example inReach routing request:
To: firstname.lastname@example.org SEND ROUTE: 10.9N, 63.8W, EMAIL=JEREMY@FASTSEAS.COM
InReach messages are limited to 160 characters, so FastSeas will by default send a single compact reply message - consisting of the next 4 positions along the optimum route at 6 hour intervals. For example:
HOUR,LAT,LNG,WIND,COG H0,11.58N,67.75W,15G18@78,126 H6,11.17N,67.16W,16G19@81,126 H12,11.04N,66.65W,10G14@110,59 H18,11.34N,66.02W,12G15@114,54
Where (looking at the first row of data):
|H0||Indicates the elapsed time in hours to reach the waypoint. H0 is the start point, now, at hour 0; H6 is 6 hours from now, etc.|
|11.58N,67.75W||Latitude and longitude in decimal degrees|
|15G18@78||Wind 15 knots, gusting 18, from 78 degrees true|
|126||Course over ground (true) from this waypoint (H0) to the next waypoint (H6)|
If you need more waypoints, you can send a request with the optional
determines how many waypoints will be sent (default is 4 waypoints), and
determines how many hours between each waypoint (default is 6 hours). For example:
To: email@example.com SEND ROUTE: 10.9N, 63.8W, EMAIL=JEREMY@FASTSEAS.COM, WAYPOINTS=24, INTERVAL=4
The example request above will send 24 waypoints with 4 hour interval between each waypoint. If you request more data than can fit in a single 160 character message, then FastSeas will reply with multiple messages. The example request above will result in a chain of 6 messages being sent in reply.
Departure planning responses to inReach devices are similarly brief. The default response will include a single day (departing today) of departure planning stats sent in a single messages. Example request:
To: firstname.lastname@example.org SEND DEPARTURE: 10.9N, 63.8W, EMAIL=JEREMY@FASTSEAS.COM
PLAN 1 DEP 16 APR 14:34Z TIME 2d4h MOTOR 0h W-MIN 11 W-MAX-BEAT 19 W-MAX-REACH - W-GUST 25 W-AVG 17 %BEAT 100 %CLS 0 %BEAM 0 %BRD 0 %RUN 0 BS-AVG 6.8
|DEP||Departure date and time in UTC|
|TIME||Passage duration, where 2d4h means 2 days and 4 hours|
|W-MIN||Minimum wind (knots)|
|W-MAX-BEAT||Maximum wind beating (knots)|
|W-MAX-REACH||Maximum wind reaching (knots)|
|W-GUST||Maximum wind gust (knots)|
|W-AVG||Average wind (knots)|
|%BEAT||Percent of the time beating|
|%CLS||Percent of the time close reaching|
|%BEAM||Percent of the time beam reaching|
|%BRD||Percent of the time broad reaching|
|%RUN||Percent of the time running|
|BS-AVG||Average boat speed (knots)|
You can request several days of departure planning results by specifying the optional
parameter in your request. The example request below requests 5 days of departure planning stats, which will result in 5 separate response
messages being sent to your inReach device:
To: email@example.com SEND DEPARTURE: 10.9N, 63.8W, EMAIL=JEREMY@FASTSEAS.COM, PLANS=5
|Commands, Parameters, and Abbreviations||Description|
||Requests an optimum routing calculation|
||Requests an departure planning calculation|
||Requests route as a GPX file rather than KMZ|
||Requests route as a zipped GPX file|
||Limit the size of the returned route to the specified number of days|
||Delay the departure time by the specified number of hours (from "now")|
||Specifies the maximum wind you are willing to tolerate forward of the beam|
||Specifies the maximum wind you are willing to tolerate aft of the beam|
||Specifies the maximum wind gust you are willing to tolerate|
||Disables ocean current effects in routing calculations|
||Used to adjust the performance of the vessel from what the polar would suggest - where "100" is the nominal polar derived performance|
||Specifies the minimum boat speed below which you will start motoring|
||Specifies the motoring boat speed|
||Associate your inReach request with your FastSeas profile (inReach only - required for all inReach requests)|
||Specifies the number of waypoints to return (inReach only; optional; defaults to 4)|
||Specifies the number of hours between waypoints (inReach only; optional; defaults to 6)|
||Specifies the number of departure plan days to return (inReach only; optional; defaults to 1)|
A polar diagram is a common way of depicting vessel performance in various wind conditions. The diagram plots boat speed at various true wind angles and wind speeds. The true wind angle is indicated around the edge of the semicircle. Boat speed is then plotted at various true wind speeds - different color lines representing different true wind speeds. The boat speed is indicated as the distance from the center of the circle. Concentric circles indicate boat speed starting at zero in the center of the circle and extending out at 2, 4, 6, 8, and 10 knots boat speed.
Edit the polar diagram for your vessel by entering boat speed values in the table below. In this table there are four columns for different true wind angles. True wind angles measure the direction of the win relevant to the bow of the vessel. A true wind angle of 0° represents wind coming directly from the bow, and 180° represents wind coming directly from the stern. Sailing vessels should enter the closest point of sail in the first column header. The table has six rows for different true wind speeds (5, 10, 15, 20, 25, 30 knots). In each cell in the table, enter your boat's speed in knots for the given true wind angle and true wind speed. The polar diagram will be automatically updated as you enter this data. Your polar will be automatically saved in your account for reuse on your next visit.
Use this option to import a polar created elsewhere; or to create a more complex polar than is possible using the Edit option above; or to export and save your polar for safe-keeping or for re-use in some other routing application.
|Elapsed Hours||Date/Time||Latitude||Longitude||Heading||Speed||COG||SOG||Wind Speed||Gusting||Wind Dir||TWA||Ocean Current Speed||Ocean Current Direction|
Departure planning will calculate estimated route statistics based on the departure date/time, start location, and finish location that you configure on the Routing tab. It will calculate these stats on one day departure intervals starting with the departure date you specify on the Routing tab. These stats are rough estimates and intended for comparison of potential departure dates.
|Statistic||Plan 1||Plan 2||Plan 3|
You have imported custom polar data. If you edit it here, your imported polar data will be modified and likely significantly simplified in order to fit the data entry screen.
Are you sure you want to proceed?
When switching between "Sail" and "Power", FastSeas will generate a new "Simple" polar and your existing polar will be replaced/lost.
Are you sure you want to proceed?
FastSeas offers a REST API to facilitate integration with third-party services and products. The FastSeas API supports weather routing, departure planning, and vessel polar generation requests. The API is implemented in a highly available and scalable architecture and is ready for your web-scale use cases. Please direct inquiries to Jeremy.
Save 50% by paying yearly
Secure credit card payment
Click "Confirm" below to cancel your FastSeas subscription.
Cancellation will be effective at the end of your current billing period on .
Your subscription is now active. Your subscription renewal date is .
FastSeas is created by Jeremy Waters. Jeremy is a lifelong sailor with extensive cruising experience spanning the Western Mediterranean (Costa del Sol, Balearics, Algeria), Eastern Caribbean (Virgin Islands through Trinidad, Venezuela, and Bonaire), throughout The Bahamas, US The US Gulf and East coasts (Florida through Chesapeake), and a transatlantic.
If you have feedback, suggestions or questions, please email them to me.
Can't find your answer?
We're here to help. Get in touch and we'll get back to you as soon as we can.
Send us an email
NOAA publishes GFS model data four times a day. The approximate times that FastSeas acquires these new data are shown below: