Search for a Location
  Clear Recents
Metro
South West
Central West
North West
  Surf Cameras
  Safety Bay Camera
Metro
North
Mid North
Illawarra
South Coast
Metro
West Coast
East Coast
Brisbane
Far North
Central Coast
Sunshine Coast
Gold Coast
Hobart
West Coast
North Coast
East Coast
Recent
Western Australia
New South Wales
Victoria
South Australia
Queensland
Northern Territory
Tasmania
  My Favourites
  Reverse Arrows
General
Gps & Speed Sailing
Wave Sailing
Foiling
Gear Reviews
Lost & Found
Windsurfing WA
Windsurfing NSW
Windsurfing QLD
Windsurfing Victoria
Windsurfing SA
Windsurfing Tasmania
General
Gear Reviews
Foiling
Newbies / Tips & Tricks
Lost & Found
Western Australia
New South Wales
Queensland
Victoria
South Australia
Tasmania
General
Foiling
Board Talk & Reviews
Wing Foiling
All
Windsurfing
Kitesurfing
Surfing
Longboarding
Stand Up Paddle
Wing Foiling
Sailing
  Active Topics
  Subscribed Topics
  Rules & Guidelines
Login
Lost My Details!
Join! (Its Free)
  Search for a Location
  Clear Recents
Metro
South West
Central West
North West
Surf Cameras
Safety Bay Camera
Metro
North
Mid North
Illawarra
South Coast
Metro
West Coast
East Coast
Brisbane
Far North
Central Coast
Sunshine Coast
Gold Coast
Hobart
West Coast
North Coast
East Coast
Recent
Western Australia
New South Wales
Victoria
South Australia
Queensland
Northern Territory
Tasmania
  My Favourites
  Reverse Arrows
All
Windsurfing
Kitesurfing
Surfing
Longboarding
Stand Up Paddle
Wing Foiling
Sailing
Active Topics
Subscribed Topics
Forum Rules
Login
Lost My Details!
Join! (Its Free)

Forums > Sailing General

Off course warning app.

Reply
Created by garymalmgren Two weeks ago, 29 Jan 2025
garymalmgren
1236 posts
29 Jan 2025 8:04AM
Thumbs Up

I posted a question about this 4 years ago.
The post is "Too Old to Repost"
Just wondering if there has been any development in off course alarms . This is especially when a solo sailor takes a nap under windvane pilotage and the vessel veers off course slowly with a wind direction change.
Here is the original post.
gary
www.seabreeze.com.au/forums/Sailing/General/Is-there-an-app-?page=1

JonE
VIC, 348 posts
29 Jan 2025 11:10AM
Thumbs Up

Gary - do you need it on an Ios or Android device?

Trek
NSW, 1166 posts
29 Jan 2025 12:29PM
Thumbs Up

How about one of these, assuming you have a device like Chart Plotter etc that outputs NMEA 0183 data. It works with Trek Transponders NMEA 0183 if you have one.

www.amisales.com.au/sku-1570510-md76-heading-mon-off-course-alarm.html

DrogueOne
209 posts
2 Feb 2025 9:25PM
Thumbs Up

Now that's a nice bit of professional kit!

Ok Gary, This looked like an interesting little app so I speced it out and have been hacking code for the last few days. I'm close but wanted to confirm a few things while I'm tweaking the interface. Nothing that is critical, just wanted to verify and let you know I may have something for you to try soon.
1. min off course angle ( and max ) 5-60 steps of 5
2. check frequency, I'm thinking minutes here not seconds, say 5 min min in steps up to a max of 1hr

The thing is while you can check every few milisec, given that you are looking for something over 10nm or so thats a 2 hr trip at 5kts so checking every 5 min or so seems reasonable to me.

I'm coding in Html/Javascript to run in a browser window. You can either get the html file from a trusted website or launch it directly fom your phone/tablet. ( simpler than building an app that has to be side loaded as I don't contribute to the app stores ).

garymalmgren
1236 posts
3 Feb 2025 8:22AM
Thumbs Up

HI D1
That sounds way above my head.
I found an app that has a off course function, but it has so many options loaded onto it that I could not figure out how to set the course and the alarm.
Too many bells and whistle is not better,
The app is called Sail Expert.

Gary

JonE
VIC, 348 posts
3 Feb 2025 12:44PM
Thumbs Up

Gary - iphone or android? This is important because I'm going to buy an android tablet today for OpenCPN.

This would be useful for people running older and less reliable autopilots too, particularly anything involving a fluxgate compass.

garymalmgren
1236 posts
3 Feb 2025 12:04PM
Thumbs Up

Hi JonE
i use Android
On (Super cheap Chinese) Tablet for Navionics and CMaps.
On phone for Boat Speed app. (Which I love)

Gary

JonE
VIC, 348 posts
3 Feb 2025 3:08PM
Thumbs Up

Thanks Gary,

I have a shiny new Galaxy tab on my desk. Watch this space :)

DrogueOne
209 posts
3 Feb 2025 1:58PM
Thumbs Up

I have a few days head start on you!

garymalmgren
1236 posts
3 Feb 2025 2:29PM
Thumbs Up

Check BOAT SPEED JON.
I paid the $1.

The font is huge, a night light setting and an audio announcement of speed.
You can leave the tablet below and get a speed reading (audio) as often as you want.
That is until you get sick of it and switch it off for ever.

I love my tablet, but be warned they are not really Moisture proof let alone waterproof.
They will slide off the table in the blink of an eye and you can't really read them in sunlight.
Other than that. Great

Gary

DrogueOne
209 posts
3 Feb 2025 2:40PM
Thumbs Up

Boat speed looks great, very polished.
I'm so close to being finished I will keep going anyway.






garymalmgren
1236 posts
3 Feb 2025 3:39PM
Thumbs Up

You'll get my dollar D1
That looks great
Will the alarm be John Cleese vocal.
"Now. Just where do you think you are going?"

Gary

Ambler
TAS, 98 posts
4 Feb 2025 8:15AM
Thumbs Up

I think a more important alarm would be a cross track error alarm which would sound when your boat strays from the desired route by a set amount. That way any side current or leeway etc could be attended to when the alarm sounds.

My old school Garmin has that alarm feature which I set when windvane steering.

JonE
VIC, 348 posts
4 Feb 2025 8:35AM
Thumbs Up

I think the use-case here is the one where there is no active waypoint, and certainly no integrated plotter and autopilot/course computer.

this probably isn't uncommon since all the modern plotters have abandoned NMEA0183 so installing a chart plotter involves replacing all your wind/depth etc.

at the same time everyone has a mobile phone or tablet and navionics so you know what direction you want to point in, you just have to set the wind vane / autopilot yourself.

garymalmgren
1236 posts
4 Feb 2025 6:35AM
Thumbs Up

Hi Ambler. RE; My old school Garmin has that alarm feature which I set when windvane steering.

That is the point Ambler.
Garmin have had this feature for 20 years or more.
Garmin bought Navionics and did almost no upgrades, so us with Navionics have to go somewhere else for a feature that should be standard.
I mean my car has alarms for everything!

Hi Jon RE; at the same time everyone has a mobile phone or tablet and navionics so you know what direction you want to point in, you just have to set the wind vane / autopilot yourself.
The point that I was making was when you are alseep under windvane, the boat can slowly change course with a windshift.
A simple alarm that sounds after you are 15 degrees off course or 5 degrees off course for 5 minutes would be great,
Nothing fancy.

Gary



Subscribe
Reply

Forums > Sailing General


"Off course warning app." started by garymalmgren