Earlier this year, I was on a yacht delivery on a 39ft trawler across the Gulf
of Mexico. The weather went crappy and we had 6-7ft following seas. The
ship's Danforth compass had poor dampening and constantly swung 40 degrees
making steering by it impossible and a broach very likely. We set a waypoint
on the GPS and entered a GO TO. Then zoomed in to a 300ft screen and steered
by keeping the line on the screen vertical. Kind of like an attitude indicator
on an aircraft. Worked like a charm.
My point is to use all available nav aids and cross check between them all.
Don, #6293, Niceville, FL
michael mcvey <[EMAIL PROTECTED]> wrote:
.hmmessage P { margin:0px; padding:0px } body.hmmessage {
FONT-SIZE: 10pt; FONT-FAMILY:Tahoma } OK time for me to weigh in I have no
GPS and the last nav aid I owned was loran C. I believe that GPS is a great
option and an asset for most but if you do not know DR you can and most likely
will get into trouble. As nice of an aid as they are nothing can replace good
old seamanship! I only say this since we do have a few new sailors on this
talkring and would like to see what they can add in the future so by all means
get a GPS but also know dead reckoning it could save you allot of headaches or
worse Phil is correct that some companies will use maps instead of charts witch
is not that big of a deal on the S.F Bay but should you get close to the east
side there are alot of shoals and shallows not to mention old piers and sunken
boats. In other words you don't always get what is advertised best of luck in
your hunt for a GPS.
---------------------------------
From: [EMAIL PROTECTED]
To: [email protected]
Subject: RE: catalina27-talk: GPS
Date: Fri, 14 Dec 2007 13:54:52 -0800
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{margin-bottom:0in;} 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 its a tiller boat question, so Id
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 Nickys plight was always included. I
also included the story of three boats that didnt 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. Its like 50 feet wide at its base and 70 tall and only about 8 feet
in diameter when it breaks the surface. Its not on any map based GPS. Map
based GPS units 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 youre 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 youd be telling your wife to
grab the ditch bag if you relied on a dumb straight down depth alarm.
Its 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. Heres 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.
Dont 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 its 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. Im not saying it must be Standard
Horizon, but dont buy a unit with less features today than the one I mounted
in ten years ago. And dont trust a salesman; have him show you the features.
Its your boat and youll 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:[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
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