I have three apps on my iPod Touch specific to boating. I find it a truely magical little device to have in my pocket. It's what all the other PDA devices I've owned never lived up to. To call it an iPod music player is a disservice, it is truly one of the best pocket computers ever built. Most of the apps I use are free, and the few I have bought cost pennies compared to most software.
The Navionics Marine 'BC Canada' app. This gives me complete set of full marine charts for all of Puget Sound and the BC Inside Passage as well as the outside of Vancouver Island. It is actually the exact same set of charts that I have on the chip in my Eagle Chartplotter/Sounder at the helm of boat. In addition to full charts, it has great easy to access tides and current information for the entire region which is essential when boating up here. At $10 it is the best bargain in the marine chart industry.
I also use Atlantis Technologies 'Tide App' for quick checks of tide levels.
Paul Brill's 'NOAA National Weather Service' App is installed for easy access to the latest NOAA marine weather forecasts. Note that it has some weird scrolling issues, but all the info is there. You just seem to have to push harder and slower to scroll the page than in any other app I have.
I also find I do most of my logbook entries on the touch (occasionally I use the Blackberry). I've used a variety of notepad apps, but at the moment have settled on '
http://www.EverNote.com '. They provide an online store for your notes and I have clients on my PC, iPod Touch, and Blackberry. You can also access the notes via any browser. Besides text notes you can add photos and voice notes. They will even do OCR conversions of text in pictures. It's a great service and is free.
I use '
http://www.toodledo.com ' for all my task storage (boat and otherwise). This is another free online service. I have their app on the touch and use the browser interface on the PC. There is a Blackberry app as well, but unlike iPod software they want a lot of money for it. The app is great for jotting down those ToDo items as you come across them as well as having your list handy while you are in project mode on the boat. I also have the Web Information Systems app 'Pocket Informant' on the touch. It is a great app that combines calendars and todo's. It syncs with Toodledo tasks and Google calendars putting all that online info in your hand. I find I use it more than the standalone Toodledo app or the built in iPod calendar app.
Two other apps get a lot of use when out boating. Amazon's 'Kindle' app for reading, and the built in iPod media app for when we want some music. However, I find I use the media app far more for books on tape which I get from '
http://www.Audible.com '. It's great to kick back and listen to a book at the helm while making a passage.
I also have all 5 of my email accounts setup in the touch for easy access as well as the MS exchange sync Google supports for calendars and contacts with my Google App domain. This gets me full access while out on the boat in the touch as well as my Blackberry which also syncs all this email, calendar and contacts info. Some may ask why have all this out boating, I find I can relax more, when I can take a quick glance at a handheld device and know that there are no fires that need to be put out, than I can when I am disconnected and wonder what is going on.
While out boating I also often use various news and info apps to stay in touch without firing up the full computer. I also find my banks app useful for managing the money side of boating.
I have a set of Sony Bluetooth wireless headphones that are perfect for listening while the iPod is safe and secure inside a pocket. Not just for boating, I find I listen to Audible books while driving almost anywhere alone as well as when doing projects around the house. The wireless headphones work like a charm making it possible to do almost any task without having problems with wire tangles. The range is around 20'-30' so you don't even have to have the iPod on your person.