A great bonus to sailors these days is the amount of processing power installed in humble devices. One is the smart phone, where essentially you have a computer with a high resolution screen that fits in your pocket.
I have a Samsung Galaxy S2 Android smart phone and there is a vast array of free applications that are useful to the sailor. Being free they're of immense interest to the Skint Sailor.
The first one I'm highlighting as I use it so much is "UK Tides", an application that is simple in that it "just" predicts UK tides. Find it at https://play.google.com/store/apps/details?id=fr.aperto.android.uktides&hl=en_GB
Here's a screen shot:
At the top of the screen is the name of the place where its predicting the tide. You can set it manually, or it can also work off GPS so it shows the tide prediction nearest to your physical location.
Just under that is the date line, which highlights the current date in white. If you swipe sideways you get the prediction for the next day.
Below that is a table showing the time of the low and high tides for your chosen location.
Below that is the sunrise and sunset times: handy if you're spending the day out at sea and you need to know if the tides are right and you have enough daylight hours to enjoy them.
Below that is moonrise and moonset and of course the phase of the moon lets you know if you have a moonless or moonlit night.
Below that is a graphical chart of the tide for the day, and a white line on the graph shows where the current time is on the graph.
Finally at the bottom is the current tide depth.
Very, very handy and I refer to it constantly.