GPS Speedo? - SailNet Community
 2Likes
  • 1 Post By fallard
  • 1 Post By chef2sail
 
LinkBack Thread Tools
post #1 of 9 Old 03-04-2018 Thread Starter
Member
 
Join Date: Jul 2016
Posts: 85
Thanks: 6
Thanked 0 Times in 0 Posts
Rep Power: 4
 
GPS Speedo?

I have been having issues with intermittent speed readings on our Raymarine ST50 and 2092? paddle wheel speedo. As you will all know, its obsolete equipment and I don't want to cut a new hole in the hull for a replacement paddle wheel.

I'm not so much of a racer but in light winds it can be difficult to feel minor speed changes when trying to trim the sails, hence I miss my speed display. Late last season I did try an app on my Iphone but the screen times out and the update rate was too slow.

I'm looking for a "cheap" GPS speed display hand held or panel mount that will work in the 0-10 knot range.

Any recommendations?

Robert
Rob_P is offline  
Sponsored Links
Advertisement
 
post #2 of 9 Old 03-04-2018
Senior Member
 
Join Date: Aug 2010
Location: The Bahamas
Posts: 4,140
Thanks: 3
Thanked 153 Times in 151 Posts
Rep Power: 10
 
Re: GPS Speedo?

You might want to try a Pad w/gps.
You can put charts on it.

I have a simple, inexpensive Galaxy Tab A.
There are many apps
RegisteredUser is online now  
post #3 of 9 Old 03-04-2018
Senior Member
 
BarryL's Avatar
 
Join Date: Aug 2003
Location: Long Island, NY
Posts: 2,324
Thanks: 6
Thanked 118 Times in 113 Posts
Rep Power: 17
 
Re: GPS Speedo?

Hey,

I don't know what you mean by 'cheap' but you can buy basic gps unit for under $100. You can get a better hand held GPS with charts and everything for under $300.

You can use an iphone or other smartphone with a $10 charting app, but it will kill your battery quickly unless you provide power to it.

Barry

Barry Lenoble
Deep Blue C, 2002 C&C 110
Mt. Sinai, NY

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
BarryL is online now  
 
post #4 of 9 Old 03-05-2018
██▓▓▒▒░░▒▒▓▓██
 
Join Date: Apr 2006
Posts: 13,645
Thanks: 11
Thanked 253 Times in 248 Posts
Rep Power: 15
   
Re: GPS Speedo?

Got an obsolete Android phone? If not, you can also buy one dirt cheap, just install a GPS speed app on it, a 12v power cord, and velcro it in place until you get a new paddlewheel.

An intermittent paddlewheel speed is usually a bad connection, corroded, loose, or cold solder joint. Could be the cable or the instrument.
hellosailor is offline  
post #5 of 9 Old 03-05-2018
Senior Member
 
Join Date: Aug 2010
Location: The Bahamas
Posts: 4,140
Thanks: 3
Thanked 153 Times in 151 Posts
Rep Power: 10
 
Re: GPS Speedo?

Maybe check for any living or nonliving things in the area of the small wheel.
RegisteredUser is online now  
post #6 of 9 Old 03-05-2018
Senior Member
 
fallard's Avatar
 
Join Date: Nov 2009
Location: Mystic
Posts: 2,344
Thanks: 20
Thanked 80 Times in 79 Posts
Rep Power: 11
 
Re: GPS Speedo?

A problem with using GPS for sailboat speed is that you are measuring speed over the bottom—not speed through the water.

If the water is moving over the bottom (i.e, there is a tidal current) you will be missing an important input to your integrated sailing instruments. Assuming your GPS data is independent, you won’t have a reading of true wind, for example. OTOH, if you don’t have integrated instruments, it probably won’t matter that much.
chef2sail likes this.
fallard is online now  
post #7 of 9 Old 03-05-2018
Senior Member
 
chef2sail's Avatar
 
Join Date: Nov 2007
Location: Maryland
Posts: 11,057
Thanks: 111
Thanked 220 Times in 212 Posts
Rep Power: 13
 
Send a message via AIM to chef2sail
Re: GPS Speedo?

Quote:
Originally Posted by fallard View Post
A problem with using GPS for sailboat speed is that you are measuring speed over the bottom—not speed through the water.

If the water is moving over the bottom (i.e, there is a tidal current) you will be missing an important input to your integrated sailing instruments. Assuming your GPS data is independent, you won’t have a reading of true wind, for example. OTOH, if you don’t have integrated instruments, it probably won’t matter that much.
If you are a fanatic about boat speed Fallard is 100% correct. I only really put my paddle wheel in when racing or trying to fine tune sail setting.

Most of the time the GPS ( speed over the bottom) is fine for us.

Only if I were a racer would I spend the money to replace a thru hull and upgrade
BarryL likes this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
___________________________
S/V Haleakala (Hawaiian for" House of the Sun")
C&C 35 MKIII Hull # 76
Parkville, Maryland
(photos by Joe McCary)
Charter member of the Chesapeake Lion posse

Our blog-
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


“Sailing is just the bottom line, like adding up the score in bridge. My real interest is in the tremendous game of life.”- Dennis Conner
chef2sail is online now  
post #8 of 9 Old 04-14-2018
Junior Member
 
Join Date: Apr 2018
Posts: 8
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Re: GPS Speedo?

STW is great for set and drift and SOG is great for speed. If you really want to know how you are doing you need both.

You can anchor your boat in a river and STW will tell you your going 3-5 knots while SOG will read 0. Or you could be drifting down the river and STW will be 0 and SOG will be 3-5 knots.

If you are interested in how long it will take you to get from one point to another STW will not hep you.

Last edited by KeelMe; 04-20-2018 at 08:00 PM. Reason: missing letter
KeelMe is offline  
post #9 of 9 Old 04-14-2018
Senior Member
 
Join Date: Feb 2010
Location: Narragansett Bay
Posts: 21,072
Thanks: 82
Thanked 591 Times in 567 Posts
Rep Power: 12
   
Re: GPS Speedo?

If one is totally chill, they can get away with GPS speed alone. Me, I'm not chill. When SOG is low, I'm all over whether the bottom is fouled, the prop is fouled or the motor working properly (if I'm motoring), did we snag something, are we trimmed properly, etc? I always check current, when out of synch. It would drive me nuts, not to see STW to be able to confirm we are actually moving at the proper speed.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Jeanneau 54DS

In the harsh marine environment, something is always in need of repair. Margaritas fix everything.
Minnewaska is offline  
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Standard Horizon speedo to Raymarine ST60 jasenj1 Electronics 1 05-05-2016 11:01 PM
Raymarine speedo question BarryL Gear & Maintenance 9 06-29-2014 03:38 PM
iPad, built in GPS or bluetooth GPS Frogwatch Gear & Maintenance 31 03-18-2014 09:13 AM
Speedo Help Please Dave_E Gear & Maintenance 10 09-16-2013 09:36 PM
B&G Hydra II Speedo bils Gear & Maintenance 2 10-06-2007 09:23 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome