The problem with that tide prediction program is that it is available only on line. If you're someplace where you can't get onto the Internet and need tides, you're out of luck. The other problem is that you have to pay for anything over 7 days worth of tide predictions for one place.
the following two programs are both free, and downloadable to your computer so you don't need to be on line to get tide predictions. WXTide I've used for years, and I like it a lot. It provides for a very easy, printable text version of the graph, and can be for several days or a month. It's easy to search for the tide datum near where you are - you can enter your lat/long and it will give you a list of stations in the area. I like the fact that it gives the lat/long of the location/station that it's using for its predictions.
JTides is relatively new, and for me it's a bit more cumbersome, but probably because I'm so used to WXTide. I've run JTide and WXTide alongside each other and their predictions are fairly close to each other - usually within 5 or so minutes, almost always less than 15 minutes.
I've run comparisons of predictions for three (3) locations using Easy-Tide, WXTide, and JTide. Easy-Tide was significantly different from the other two programs: for one location there was a 2-hour difference, another 1 hour, the third between 1/2 and 1 hour difference. I used locations that from past use I knew were correct to within about 15 minutes with WXTide. Some programs are just not going to do a good job in some areas - the use of different reference stations is the usual culprit, so my test is of somewhat limited value.
http://wxtide32.com/
http://vps.arachnoid.com/JTides/
I've checked WXTide in the past against locally-provided tide tables to give me an idea of the tolerances. I don't think any tide program, or tide table, should be slavishly followed - there are always going to be some kinds of variations for many reasons. Yet since Peter and I have an affinity for tip-toeing into marginal depths, knowing the approximate times of high and low tide, and most importantly the tidal range, keeps us from going high and dry and in need of outside help. With our proven ability to find Internet-DEAD zones, I don't want to rely on an internet connection to plan our forays.
Just a few more little items to add to our tool chest.