iPhone at sea

[Tony - Santana]

Strictly, this is not a Morgan Giles 30 subject, but the very limited
space aboard Santana for electronic instrumentation, not to mention
cost, has kept me away from advanced modern electronics such as chart
plotters and radar, etc. I have just VHF marine radio, digital echo
sounder, NavTex and Garmin GPS with a repeater dislay in the cockpit.

For many years I have also carried a hand-held GPS which I loaded with
a duplicate copy of the waypoints and routes in the Garmin, and ran as
a hot standby in case the Garmin or power failed. This proved its
value one very dark and stormy night when we were approaching St
Hellier through the NW passage when the Garmin GPS stopped working. I
was too wet and tired to take sights, and working on the chart table
under those conditions would probably have added 'sick' to the list of
my woes. So I was very grateful to switch over to the hand-held
device, until I eventually got the Garmin back. [A restart seemed to
clear the problem.] So at the start of this season, when I found my
hand-held could no longer get a fix, it was important to replace it.

And here I made a radical decision: instead of paying out money for a
modern hand-held GPS, I took the plung and paid out money for an
iPhone. I have to say it has revolutionised life on-board and our
recent cruise to and from the Scilly Isles. I thought I would share
this experience with you. Now the iPhone is not rugged nor waterproof
for in-cockpit use, but I discovered it works very useably inside a
Aquapac waterproof camera bag. It takes a bit of care to use the
touch screen through the thick layer of plastic, but it is useable.
Given the limited battery life when sealed in the bag without the
charging cable connected, I also purchased an InCase PowerSlider,
which both protects the iPhone and doubles the battery life. This
worked well in these two ways, but unfortunately in my experience
cripples the GPS reception and weakens mobile signal reception, so
when I really needed the iPhone for navigation I had to remove the
case. And now to how I used it:

First, one touch on my home screen each day displayed that morning's
Met Office four-day pressure model. Weather predictions were vastly
improved, as was advanced planning, such as where to be when heavy
weather arrived, and when a fair weather window might appear.

Second, another touch and the latest shipping forecast or inshore
waters forecast was on my screen. Only twice, when out of mobile
phone range, did I have to resort to listening to the coastguard
transmission and try and write it down accurately. With the forecast
in written form on demand I could study it and relate it to the
pressure chart to understand the basis of the forecast and reach my
own judgement on what to expect - not always the same.

Third, I had purchased iNavX from the Applications Store, a marine
application, which provided all I got from my old hand-held GPS and
much more. With iNavX I was able to load in my waypoints and routes
and there was the functionality of a hand-held marine GPS. But
additionally, compared with my old hand-held, iNavX provided my
position, waypoints, routes and track plotted on marine charts from
Navionics, which are available through X-Traverse for just $39 for the
whole UK and Ireland waters. Although raster based, these charts
proved excellent and with great detail where needed.

Fourth, tidal hight calculations were handled by the application
AyeTides, which, knowing my position, offered a choice of the closest
ports or places where it had data and then displayed the tidal curve
with the present time indicated upon it, together with present height
above chart datum and the height of the coming low waters. The coming
tidal drop was, therefore a trivial deduction, enabling me to know
exactly how much depth I needed to anchor. Given there were no
extreme barometric pressures or storm surges on this trip, I learnt to
judge it finely, and, when over an even bottom, I sometimes left just
one foot spare for low water, which proved very accurate. Finding our
way into an anchorage, the chart display in my hand at the tiller
proved invaluable. I found it possible to use this to edge close in
turning to port or starboard for the deepest water as shown. After
our return crossing from the Scillies we used this to particular good
effect at night to tuck ourselves snuggly into an anchorage in the
unlit Helford River.

Fifth, the BlogPress application allowed me to run a cruise blog to
keep family and friends apraised of our whereabouts and well-being,
including selected photos taken on the iPhone.

Sixth, when gazing in wonder at the stars and curious about what we
were looking at, launching Starmap and pointing the iPhone at the sky
provided the answers and more.

Seventh, and last here, we were able to keep in email contact and even
make phone calls!

Some cautions: Wisely, I did not over-rely on this new technology and
carried a full set of up-to-date charts. I cross-checked with other
information, and necessarily too. The iPhone position was not as
accurate as the Garmin, with its external antenna, and sometimes it
lost its GPS position altogether. It then fell back on cell-tower
positioning, but since there was at best only one tower available,
would suddenly teleport us to some nearby town or airfield where the
tower was located. Particularly in chart view, this was immediately
obvious. Sometimes it seemed necessary to restart the application or
even the iPhone to re-establish a GPS position. And uses one, two,
five and seven above required a mobile phone signal, only available in
coastal waters and then not everywhere.

Nevertheless, my experience has been extremely positive, and I look
forward to further developments. iNavX is also capable of displaying
other on-board NMEA data, including AIS data from other ships, relayed
from its companion program MacENC running on a laptop. There is no
room to run my laptop when under sail, but maybe a future 'iTablet'
would help here?

Declaration of interest: I hold shares in Apple (AAPL).