Tides and Currents

One of the first things I do when planning a sailing adventure is to determine what the currents are for the trip. This is important when sailing in Puget Sound and farther north in the Strait of Juan de Fuca, the San Juan Archapeligo and the Canadian portions of the Salish Sea(the new name for the inland waters of British Columbia and Washington State). With racing, proper knowledge about the currents can make the differance between a good placing and a poor placing. And when cruising, not utilizing the current information available can add hours to the length of a voyage.

When I first started sailing, all we had was a NOAA Tides and Current book. The daily predictions were published for the main current reporting stations(like Bush Point, The Narrows and San Juan Channel) and the other locations had to be calculated by the correction factors for specific areas based on the primary reporting station. Bush Point was the primary for northern Puget Sound and Admiralty Inlet. Tides were calculated in a similar manor with Seattle being the primary for Puget Sound.

The nice people of Microsoft bought a program called Tides and Currents. This is a nice tool for determining tides and currents for anywhere, no additional calculations required. I usually print out the daily predictions that I plan to sail or race in. I also have it installed on the boats navagation computer.

Another tool became available to me when I started using a Palm PDA. It is a freeware application called Tide Tool. It calculated the same data on tides and currents as well additional data on the phases of the moon and the rising and setting time of the sun. The tide and current data can be displayed as a graph in real time(a cursor points to the graph at the current time of day and reports what the current velocity is) or in table format. I carry this with me when I am on the boat and can have instant access to tide and current information if I don't have the information already printed.

I know the Palm is considered archaic now, but I would imagine that Iphones and other smart phones have similar information available as an application. Newer marine GPS's also are likely to have a tide and current tool built in. Mine is a few years old and only has tide information, no current information.

In addition to the electronic tools available, there are still books that show charts of Puget Sound and the direction of the current flow for differant phases of the ebb and flood.

A typical print out of a daily prediction for the currents San Juan Channel(south entrance). Other formats are available.

A Tide Tool display on the Palm in graph mode.

A Tide Tool display on the Palm in table mode.