In early April, the brand new, 960-foot cruise ship Carnival Spirit departed Helsinki, Finland bound for Miami, FL, a voyage of over 5,000 miles. To obtain weather data during this voyage, Spirit’s crew depended upon Inmarsat satellite communications, which allowed them to download compressed weather files from Ocean Routes, a commercial routing service, as well as access the Internet and obtain National Weather Service Marine Prediction Center products.
I was aboard for this voyage and I brought along a Global Star satellite phone and a laptop computer loaded with the latest version of SeaStation 2000, a premier weather access software (www.ocens.com). Global Star provides satellite voice and data communications and allows both ftp and http access to the Internet at a data rate of 9,600 baud.
What can this do for a mariner? Within SeaStation is a directory of all world meteorological organization (WMO) weather charts available on the Internet. This directory is linked with the specific Internet addresses (URLs) of each chart and so that when a desired chart is selected and the "download" button clicked in SeaStation, the GlobalStar phone allows that chart to be saved into the SeaStation directory. With this portable system, a single chart requires approximately 20 seconds or less to download.
Why do I mention this and is this capability useful to mariners? Well for myself and others who have struggled with obtaining charts via weatherfax, where one chart takes 10 to 15 minutes to print out, and is often so unreadable as to be nearly useless, this SeaStation-GlobalStar capability is truly impressive due to its speed and reception quality.
Accompanying this article is the 96-hour, surface-forecast chart that I downloaded on April 17 while on that trip. During the downloading process I had the choice of viewing each chart on line or downloading a batch of charts, logging off, and then opening each chart within SeaStation. For cost effectiveness the recommended process is to create a "batch download" menu within SeaStation, essentially a shopping cart of charts you would like to obtain. When a batch has been created, and the "download" button clicked within SeaStation, the software goes out to the Internet using the GlobalStar connection and without further action by you the user, downloads each chart—one by one—into the SeaStation download directory. Within the directory charts are ordered by date and type.
While I wrote this article, the Spirit was positioned at 39N/32W on a heading of 249 degrees true, 20.6 knots. We were abeam of Flores, Azores, sitting in the middle of the Azores-Bermuda high pressure. There was a low swell coming in from the west, about four to six feet, while local seas were less than a foot since the winds were below 10 knots. That was good weather for a large steamship since we wanted to avoid head winds and large swells as much as possible.
Using the Marine Prediction Center’s 24, 48 and 96-hour surface and 500-mb charts we were able to determine an optimal route for reaching Miami by the morning of April 24. Spirit is the Carnival cruise line’s newest ship and there was a busy schedule planned upon arrival in the US. The owners had made clear that avoiding heavy weather on this maiden Atlantic crossing was a priority.
SeaStation’s weather chart directory assists greatly in obtaining the most appropriate charts regardless of the time of day because within each product listing there are choices listed by valid time as well as by "most current." How is this useful? Because I no longer need to be concerned with broadcast schedules as I was when using wefax. Regardless of the time I always chose "most current" when downloading either individual charts or building a batch download. I allow SeaStation to compare the time of chart release to the present time and pull down the "most current" product.
Once my selected charts are downloaded, I open them within SeaStation, overlay a latitude/longitude grid, and then input GPS data, which places a cursor at Spirit’s present position. I have turned a weather chart into an electronic chart on which I can navigate until the next appropriate weather chart is downloaded. For me, there’s no better way to navigate on the open ocean than by using a weather chart since wind, waves, swells, clouds are the most important navigational features in this setting.
Of course, once I finished this article I had two options: send it to SailNet via GlobalStar as an attachment to my e-mail, or transfer it to a floppy disc, take it up to Spirit’s bridge, and send it via the ship’s Inmarsat system. Since I am always looking for reasons to spend time on the bridge (there is a terrific espresso machine in the pantry), I chose the option of sending via the ship's satellite communications system.
I remember the satisfaction I had being able to send the article off with full confidence that it would arrive easily by the deadline. I wasn’t actually sure when that was, but at that particular moment, life under the Bermuda-Azores high pressure was extremely pleasant and I wasn’t too concerned. All our navigation concerns were attended to, and I had a great cup of espresso in my immediate future.
Performance Basics for Routing by Michael Carr
Advanced Electronic Charting by Jim Sexton
WAAS Up? by Don Casey
Buying Guide: Chartplotters