Making final decisions can be hard. There's a fair amount of "buyer's remorse" from simply making the decision. And it's a religious kind of experience. A chartplotter represents a search for truth in a world of uncertainty. We're seeking confidence that we're doing the right thing. Really.

I started by wringing my hands over computerized charts. See "Charts". I'm not done with this hand-wringing. The "general purpose computer" question weighs on me heavily.

I've wrung my hands over integrated GPS Chart Plotters. See "GPS Chart Plotter -- Need or Nuisance?" While I'm sold on the Standard Horizon CP300i, Karl of White Pepper said that Garmin "Just Works". And Brooke of Liquid Therapy, similarly, likes Garmin's ease of use, but he's also a Mac ENC user. The skipper of Soul Mates wasn't happy with his Raymarine because the cartography wasn't very accurate where it mattered in the Bahamas. Henry of Legacy says they all have problems.

I think that's the important observation -- they're all a mix of good and bad as well as being more similar than different.

They're good because they serve an important need ("Where are we?" "Which mark is that?" "How long will it take to get to Jackson Creek from here?"). They're bad because -- as with any tool -- they're not perfect. They're just a tool. And because they include one (or more) computers, they're a complex, and prone to the problems that stem from that complexity.

You -- the skipper -- integrate information from various sources. Depth, marks on shore, GPS, your recollection, your experience.

All we want is someone to tell us what to do. It's a very religious experience. We want a chartplotter to be the voice of God -- absolute, unwavering, reassuring, certain. The information pours down from heaven. How much more religious can a chartplotter be?

We search for God to tell us where we are; we want God to plot the right course for us to get somewhere. Eventually, we find that this metaphor is too simplistic. God's path may be absolute and unwavering, but we're not understanding it clearly. We're forced to integrate all the information at our disposal and make decisions fraught with elements of uncertainty. God is confusing and requires us to think. Sigh.

Does Nothing Well

A general purpose personal computer (or iPhone) does everything. Consequently, it can't do a particular thing very well. Computers are fragile. Software installs and upgrades are usually beneficial, but sometimes the upgrade breaks legacy software. Application software involves a large number of interdependent parts. Open source software involves a large number of independent and uncooperative parts. [I'm a Macintosh fanboi, so viruses are not a concern, thanks. Software is already complex enough without worrying about malware.]

While we're inexperienced, we do see two distinct use cases.

1. Navigating.

2. Planning.

A dedicated chartplotter looks like it will help us with navigation. Push a button a find time-to-waypoint (TTW) or course-to-steer (CTS). Real-time GPS feed. No paper blowing around the cockpit. The little blue boat floats across the charts automagically. But the cockpit-friendly units don't seem like they'd support planning well. Planning is a mouse-and-keyboard task. It's done from the comfort of the nav station, when it's quiet and there's a lot of time to dream and ponder the charts, the guidebooks and other cruisers' blogs.

Software Comparison

I tried OpenCPN. I really liked it. Usable, friendly; elegant chart quilting; nice route planning. But I could only use version 1.3; there's little Mac OS support. It crashed frequently. Sigh.

I looked at GPSNavX and MacENC. They're nice, too, but how to choose?

Before I could formalize my hand-wringing into a big white-paper and comparison table, I stumbled on this: iNavX for the iPhone. Wowza! This allows some experimentation with navigating and planning without a fragile computer on deck.

Sunday (the 29th) we dropped our list of chores and pottered around using iNavX on the iPhone.

Planning and Navigating

While playing with OpenCPN, I'd created a route: a 100nm trip to Galesville, MD, site of the 2010 Whitby-Brewer Rendezvous. The initial draft of the route wasn't very good because it skirted some known obstacles a little too closely. I couldn't update it with OpenCPN (it crashed too often) so it has become my benchmark for planning.

But I could use X-Traverse to download this flawed route to my iPhone. Yes, it's indirect and frustrating to have to use a third-party's web site to exchange data between my computer and my phone. They need to fix that.

I could -- to an extent -- edit the route on the phone. More usefully, I had a pile of waypoints on the phone and could easily add more. We used these waypoints -- flawed as they are -- to sail out toward the Stingray point lighthouse.

Then the wind died.

We used my waypoints to motor back to Piankatank River to practice anchoring near mark #6, labeled Q R 15ft 4M "6". (Quick Flashing. Red. Fifteen feet tall. Visible for four miles. Number "6".)

The planning on the iPhone is -- at best -- meh. It works. But it's a winky little phone screen. There's a lot of room for confusion between "scroll the chart around", and "move that way point over here".

Navigating on the iPhone is not so bad, however. Pick a point. View it on the chart. Or view the "instrument" display to see bearing to waypoint, distance to waypoint and cross-track error. Very nice.

Well... nice within certain constraints.

As long as the phone was (a) amidships and (b) aligned directly forward. When you turn to look at something, and wave the phone around, the phone's internal compass doesn't know if the boat is spinning or not, so your bearings aren't perfect unless your phone's alignment with the boat is perfect.

Clarity of Purpose

Here are some of the lessons learned.

1. God's plan is challenging; the truth is difficult to discern. No one source can be trusted implicitly. We're forced to judge for ourselves.

2. Navigation is simplified by a chartplotter, even when it's as small as an iPhone. It's very helpful to know you're headed in the right direction even if you can't see the destination yet.

3. Big-picture planning really is easier done with a computer. Small-picture decision-making ("It's getting late, is there anywhere closer?") can be done on a chartplotter, but it's hard. We pulled out the paper chart for the Piankatank because it's easier for two people to look at a big piece of paper than it is to try and squint at the phone.

4. We don't want MacENC's "drive-the-boat" capabilities. We only want GPXNavX's planning capabilities. We'll need an NMEA 0183 to USB interface to share waypoints and routes between chartplotter and computer.

5. There's no room at the helm for the chartplotter. The binnnacle is just too small. We need a bracket that's 5" long at 4" wide. The Edson 831ST-5-100, or the RAM 109V, might be just the item to clamp onto the helm pedestal.

Seeing a chartplotter in action -- even a small one like iNavX on an iPhone -- gives a compelling glimpse into the possibilities that are out there. Knowing where you are is a real confidence builder.

First things first: (1) finish the sail covers (2) find out why the engine overheated on Sunday. Then we can explore with more confidence.