Only eight (now five!) days till the start of my travels. I've agonized, like last year, over my pack's base weight. Unfortunately, it looks like it's going up a little. The switch from a tarp to a tent added about an ounce (I'm leaving behind the bivy). I'm leaving a couple of weeks earlier, so I will take an extra t-shirt for (dry) night insulation and maybe warm days. I've got a couple of ounces for a cup and lid for protein shakes. But my biggest increase is in electronics.
I need reading glasses for up close, at least for anything other than large text. But I don't like taking the glasses out of my pocket on the trail. So trying to read my 4" iPhone last year on the trail without glasses was a real pain. This year, I have the largest iPhone. Lots easier to read, but with the LifeProof case, the weight went up to 8.7 oz, a large increase. I also will be taking a DeLorme inReach Explorer, another 6.9 oz. I don't think the Explorer is needed on the AT for SOS use. But I want to be able to report my location (and progress) at campsites. It also gives me some texting or email capabilities when I'm out of the AT&T service area of my phone.
So, instead of an 11.2 pound base weight, I'll be carrying a 12 pound base weight. For a weekend, it's easy to get under 10 pounds. But for the AT, I just can't trim enough. I should mention the iPhone is carried in a pants pocket, so it adds to the 'skin out weight' and not the pack's 'base weight'. But it does require me to have a better, tightened belt for the pants to stay up. (:-)
Like last year, I'll use a page or two from the AT Guide to monitor my progress during the day. That gives me official campsites and water sources. Guthook's AT Hiker app provides GPS positioning, altitude, upcoming water and campsites, and a small area of topo maps around the trail. What I didn't like about AT Hiker, and I cannot be sure they haven't improved it, was the tedious actions of turning on and off the GPS and panning the maps and altitude plots. The app's information content is exceptional. But the user interface was awkward.
To supplement the AT Hiker, I wrote the Hikers Assistant (iOS) app this last fall (its on Apples app store). Currently, it's optimized for shorter hikes. However, I've set up five 'files' with tracks, mail stops, hostels/hotels, and shelters corresponding to five roughly 400 mile sections of the AT. The tracks use the old 2008 data available on the Internet, so there will be discrepancies with the current path of the AT. But I figure it will be good enough for most sections. While I could download USGS topo tiles for the tracks, the time and memory required don't seem worth it.
With Hikers Assistant, unless I'm recording a track, the GPS is turned on only long enough to get a position. I don't have to do anything but touch the button requesting my position, or the distances to the points of interest I've loaded. When I ask for my position, the app also indicates how far off the trail I am, and in what direction. I can likewise get the distance and bearing to any point of interest, such as the next shelter or my mail drop post-office or hostel. I'll use the Hikers Assistant app whenever possible and minimize my use of the AT Hiker app, thus keeping battery drain to a minimum.
Speaking of which, the battery on the iPhone 6s Plus seems to be about twice as big as that on the iPhone 5s I carried last year. So I'm taking a 3300 mAh backup battery (2.6 oz), just in case. I can always get something bigger if I have problems with battery use.
I'll again take my waterproof Ricoh camera to take most pictures. I use an Eye-Fi SD memory card that lets me transfer photos from the Ricoh to the iPhone at the end of the day. I wish there was a low-power Bluetooth SD memory card (the Eye-Fi is WiFi), but I can't find one. Transferring photos at the end of each day is a big power drain on the Ricoh and to a lesser extent, the iPhone. Of course, I save a lot of iPhone battery by not using it to take the photos in the first place.
I have an Eye-Fi cloud account, so when I get to free WiFi or a strong AT&T signal, I can backup all the photos to the cloud. Those I want to keep, I can transfer over to Google Photos (previously Picasa) web albums via the Web Albums app on the iPhone. When I want to add a photo to my daily blog, I can use URL links from the Web Albums app embedded into the blog text in the Blog Touch Pro app.
But I actually want to draft my blogs in Hikers Assistant. In that app, I can get an image of the day's elevation profile and specs on my day's hiking with just the touch of a button. I tell the app when I'm starting to hike and when I stop (plus lunch breaks). The app uses the nearest points on the trail as the start and end of the elevation profile. It also uses the length of the track between those points as the distance hiked--although I can also make manual adjustments for side hikes. If I draft my day's blog in Hikers Assistant, I also have a backup of the text in case the Blog Touch Pro app (which uploads the blog to Google Blogger) loses a local blog before I get to a usable cell or WiFi signal.
I suspect I'm going to have to wait till town or hostel stops to add the photos to the daily blogs.
One last thought, since I titled this to include Navigation. I wear a Suunto Core watch that in addition to showing the time, can give your heading or elevation. I can get both of those in Hikers Assistant, but with the watch, I don't have to pull out the iPhone or use iPhone battery. I'll also carry a Fitbit Zip, to give me daily steps, a rough distance, and a rough number of calories used per day. I'm just curious how close to the commonly cited five million steps the trail will take (again being optimistic about my chances).