Tom,

 

There are good units out there. As far as seeing what's on charts, even on
my unit, Standard Horizon had to make some decisions on what to show you at
what level of zoom. The display, and this is why bigger is better, only has
some much resolution so when your zoomed out many fine details would be an
indistinguishable dot and not a chart symbol at all. So in the "Big Picture"
view many details are suppressed.  When you zoom in the details begin to
appear.

 

When my brother went to Mexico a few years ago I did shore support (back
seat navigation). Before each hop after meeting with the other skippers he
was sailing down with he would email me the waypoints from his CP150 and I
would validate his route and use a couple of internet resources to forecast
wind and sea conditions while they slept and send it back.

 

What I did was enter the waypoints and then use the joy stick at the highest
resolution follow his route looking for hazards. I only caught him running
into one fixed oil platform, so he was doing fine on his own except that day
they were in a thick fog. The oil platform only showed on the highest
resolution view of this particular coastline chart. Like many boats of that
size the radar display is at the nav station below, so it goes mostly
unmonitored until something special comes up.

 

The center cockpit console on the biggest Catalinas with radar overly GPS
chart plotters in the cockpit really change the game. But even then you need
your paper charts as a back-up. 

 

Phil Agur                             s/v Wing Tip

Secretary/Treasurer     Call Sign WCW3485

IC27/270A                          MMSI 366901790 

 <http://www.catalina27.org/> www.catalina27.org    Vessel Doc# 1039809

 

-----Original Message-----
From: [email protected]
[mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
Sent: Monday, December 17, 2007 7:43 AM
To: [email protected]
Subject: RE: catalina27-talk: GPS

 


Thanks everyone ... 

I was at Cabala's yesterday and looked at some units before reading Phil's
post this morning. I was wondering, cause I wasn't seeing the data that
shows up on my charts. I didn't realize that someone would be irresponsible
enough to market such crap to boaters. Thanks for clearing that up. I think
I'll go ahead and mount it on the bulkhead by my other instruments. I was
thinking that swing-out mount sounded like a good idea, and then I thought
about how most of the time I'm doing DR anyway, and really want the thing
when visibility goes down, which probably also means I have the companionway
closed. 

Anyway, thanks, all, for the responses. Appreciate your input. 

Merry Christmas, 
Tom 







"Phil Agur" <[EMAIL PROTECTED]> 
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12/14/2007 03:56 PM 


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RE: catalina27-talk: GPS

 


 

 




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 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 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. 
1.        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. 
2.        GPS must be chart based, showing water depth, and submerged
obstructions. How about a field of submerged dols? 
3.        A great GPS can use chart data to sound an alarm on depth in your
path. 
4.        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 
 <http://www.catalina27.org/> 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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