North U Tactician App

There’s lot of new cool apps coming out for us sailors. Many are just a quick fix to solve a common problem, but some goes a bit further to take advantage of the iPhone or iPad (or Android) in a more ingenious ways.

I recently stumbled upon the North U Tactician App, and really liked the simple but clear representation of multi-dimensional data. Since the app was released just last week, we still have to try it live.

I became curious on the background and philosophy of the app, so I asked Stephen Jones to write something.

The intent of the app is to give the tactician on a racing yacht a new way of keeping track of port and starboard headings, as an alternative to writing them in a notebook or even on gelcoat. Then, taking advantage of the computing power in an iPhone, the app remembers key data points and calculates useful angles. This relieves the tactician of the short-term memory and mental arithmetic burdens, allowing him or her to focus on the bigger picture. Further, the app displays the data graphically, which helps bring out patterns and trends.

The app puts into practice the principles taught in the North U. racing tactics courses. In fact, the graphing screen of the app is a deliberate recreation of a table that appears in one of the North U. texts. (See the attached image.) Software can automate much of the note-taking, and is much more flexible to change the presentation of the data, or change assumptions. One thing we are able to do in the app is to reverse the flow of time, so that more recent observations are at the top. This is an example of breaking out of paper-based conventions, which one can really only do with software.

We were using an early version of the app on a Farr 30 last summer. At the time, the app would only display the port and starboard numbers in the history table. I think by mid-summer, the app remembered the highs and lows. Even in that crude version, we found it to be a big improvement over pencil and paper. It quickly became apparent that you need to be able to open any datapoint and make corrections. The most common error is to tap starboard instead of port, or vice versa. Such an error throws off the highs and lows quite dramatically. Now, you tap and hold a row in the history table to call up a screen to edit a record and save the changes. The edit feature added unplanned development hours, and delayed the app but I am glad I made it a priority, because the app is almost unusable without being able to correct an error.

Another new feature that came up in testing with North is the ability to change the baseline time, so that the tactical analysis ignores readings prior to a selected time. For instance, you could have the app only tell you the highs and lows on each tack since the start of the day’s second race. This is particularly important if there has been a major wind shift.

The intent of the app is not to invent a new tactical tool, but to use existing sources of information like the boat’s digital compass, and improve record keeping and data analysis on that information. The app therefore makes no use of an iPhone’s internal GPS, but instead relies on the tactician to enter the yacht’s heading into a keypad. Some might find this manual data entry approach unsophisticated, but it is a chief virtue of the app. It uses the most readily accessible and reliable instrument on the boat: the compass. Please see the Frequently Asked Questions for more thoughts on the iPhone’s internal GPS.

The app makes no attempt at any sophisticated algorithm to arrive at a weighted average for the wind direction. Instead, it simply detects the max and min headings, and initially finds the midpoint between the two. The user can then fine tune this initial starting position. Early on in my thinking, I had considered ways to automate the identification of the average wind direction, but abandoned the plan. I did not want to frustrate an experienced tactician who would find that the app is forcing him or her to accept a tactical analysis that runs contrary to his or her experience or intuition. There really is no generally agreed upon method for determining an average wind direction and updating that direction in the light of new information. If there was one, we would all be using it. The upshot is that the app is suited to tacticians of any experience level. It finds a good starting point for a novice user, but it allows an experienced tactician to move the markers as his or her intuition dictates.

The app is focused on typical windward-leeward racing. I don’t see the app being a key tool in a coastal race, for instance. Within the context of windward leeward racing tactics, the app deals primarily with upwind tactics. Downwind angles are much more volatile, so at least for this version, the app makes no inferences about true wind direction from port and starboard headings on the run. See the FAQ for further thoughts on this. We would like to tackle downwind tactics in the next version. I’m open to suggestions.

I see this app finding its niche in boats that carry sufficient crew numbers that someone has the job of watching the numbers and reporting on the patterns and trends. These boats may have basic or even mid-range instruments, but these boats still have crew members using pad and pencil to keep track of port and starboard tack headings. Given the challenges of calibrating instruments to the point where you get reliable true wind direction solutions, I think it will be possible with this app to detect windshifts more accurately and with a finer resolution than the acuity of a typical mid-range instrument package. I am quite confident that using this app one can detect windshifts much more easily and accurately than with pad and pencil — and that is precisely the intent of the app.