Phil,
Good info on very important points all mariners should keep in
mind. Redundancy on a boat is usually a good thing, especially when
the power goes out!
Herb Clark
[EMAIL PROTECTED]
Chico Yacht Club
s/v Imagine Catalina 270
s/v Hotel Charlie Catalina 25
d/s Coyote Coronado 15
"Why worry when I can sail?"
On Dec 14, 2007, at 1:54 PM, Phil Agur wrote:
I tend to get on a rant when it comes to GPS. They are not all
created the same and it appears the most popular are the worst
functionality wise and many models represent an actual hazard to
mariners. The GPS suppliers get a little cagey by making up
terminology regarding what they supply that they get to define
reality leaving any collisions with uncharted islands the mariners
fault.
So what do I have and where is it mounted. Mine is a Standard
Horizon CP150 (no longer available, as far as I can tell) on a
fixed mount at the wheel. The current low end is a CP180. Since it
runs in either north up or forward up modes have it fixed gets very
handy. I know it’s a tiller boat question, so I’d say the bulkhead.
The caveat mariners ran into in the past was the source of the
charts supplied in the non-marine professional marine GPS units was
from a map database not a chart database. They determined position
with good accuracy, did waypoints fine, would leave electronic
bread crumbs, and would direct you home down the return path. When
I warned Nicky, an avid ocean small boat angler, on a Friday
afternoon about his new Garmin GPS on his new boat he scoffed
(Nicky was a younger bright engineer at Intel) but on Tuesday he
was a little more humble. Nicky tore the I/O drive out of his new
boat Saturday. He set electronic bread crumbs at high tide on the
way out as he passed over a line of rocks that would be shoaling
rocks at low tide. On the way back in the uncharted (uncharted on
his, charted on mine) rocks waited for him just under the surface.
When I taught an intro to navigation Nicky’s plight was always
included. I also included the story of three boats that didn’t want
to hang with the main group of boats on a whale watch cruise out of
Monterey, CA. They chose to sneak off to Stillwater Cover in
Carmel, lost track of time and returned well after dark. All three
skippers were running without charts and guessing their position by
shore lights. When asked they said it was no big deal and estimated
they were a good half mile offshore.
The good news is they all three made it back the bad news is their
path took them in close proximity to a rock pinnacle that shoals a
half mile off shore at low tide. It’s like 50 feet wide at its base
and 70 tall and only about 8 feet in diameter when it breaks the
surface. It’s not on any map based GPS. Map based GPSunits besides
missing all depth data only show obstructions big enough to contain
a road.
The fun one around SF Bay was to have them look for Alcatraz
Island. Not there! After some years is was added so I had them look
for Red Rocks, again not there. Actually there literally dozens of
un-mapped hazards on SF bay that are clearly charted on the real
charts.
Besides a true marine GPS having charts, some of them are using a
chart database and not just a chart image. My GPS, and I would
assume the newer Standard Horizon GPS units as well, can have an
alarm set for depth out in front of the boat. Yes while you’re
giving instructions on the next tack it is looking at its internal
chart database and based on the depth and distance you preset will
sound an alarm before you reach the obstruction.
A chart reading forward looking alarm beats the heck out a dumb
straight down depth alarm. In the case of the rock pinnacle you’d
be telling your wife to grab the ditch bag if you relied on a dumb
straight down depth alarm.
It’s also pretty important since my GPS will directly send command
to my Autohelm. The more automated things get the more you can do
but the less oversight actually goes on. Here’s automation that
checks my work even when I get tired.
Another feature on Standard Horizon GPS units is they interface
directly with your Standard Horizon DSC VHF. When you hit the
digital Mayday key on the VHF it automatically sends your ID, GPS
location, and type of emergency. Actually most any GPS with a
NEMA0183 interface can do that, but on my boat if I receive a DSC
mayday is automatically plotted on my GPS as a waypoint and
highlighted. Before I even pick up the Ram Mic to reply I can plot
a course and estimate an arrival time on scene in the GPS.
Don’t you wish the CG had just bought the right GPS and radio combo
back in the 90s instead of the system we are all still waiting to
see deployed beyond a few test zones? Wow for under a $1000 they
can receive a DSC distress signal and plot it’s position without
human intervention and head directly there.
To review GPS is good, the right one will save your life, making it
great.
Fixed mount trumps hand held so the display can be used forward as
up. It helps keep you oriented correctly when fatigued in low light.
GPS must be chart based, showing water depth, and submerged
obstructions. How about a field of submerged dols?
A great GPS can use chart data to sound an alarm on depth in your
path.
A great GPS will plot distress calls automatically so we can assist
mariners in distress, when we are in a position to do so.
My brother was a real Garmin fan but when he prepped his IP38 for
Mexico I made him a custom mount for a CP150 at the wheel. It was
still performing flawlessly after a year when I joined him in Cabo
for the bash up to San Diego. I used it to steer around sea mounts
coming up the coast and we logged a consistently smother passage
than the boats we were traveling with us who ran straight lines.
So yes at the wheel not down below.
Ok, but I did warn you about the rant. I’m not saying it must be
Standard Horizon, but don’t buy a unit with less features today
than the one I mounted in ten years ago. And don’t trust a
salesman; have him show you the features. It’s your boat and you’ll
be the one out there when things go wrong.
Phil Agur s/v Wing Tip
Secretary/Treasurer Call Sign WCW3485
IC27/270A MMSI 366901790
www.catalina27.org Vessel Doc# 1039809
-----Original Message-----
From: [email protected] [mailto:catalina27-
[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
Sent: Friday, December 14, 2007 8:49 AM
To: [email protected]
Subject: catalina27-talk: GPS
On a tiller C27, where do you all mount your GSP chartplotter ...
or do you prefer a handheld (my family is collaborating to buy me
something useful for Christmas rather than ......... well, I'll
leave it there).
Tom
