Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 16-10-2017, 02:51   #1
Registered User
 
GILow's Avatar

Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,112
Navigation challenge - hitting a bullet with a snail?

OK, this may become one of my silliest posts yet... but please, hear me out.

This summer (December in the Southern Hemisphere), the Volvo Ocean Race boats will sail from Cape Town to my old home town, Melbourne.

Let me tell you, as a Melbourne boy, born and raised... I have no idea why they are sailing to Melbourne. But they are. They probably have a good reason.

Anyway, I will be in Adelaide as they sail past to the South of me, and I am wondering if it would be possible to sail out there into Bass Straight and actually watch them sail past. As in, get them in sight at least.

Initially I thought "Not a chance." I mean my boat does 6 knots on a good day, and those things are doing 25 or more.

But... then... I only have to sail North/South, to intercept them... and their location and course are pretty well known in near real time.

What do you navigator types think? Possible?

Oh, and I already know the idea is totally silly, so no need to point that out. I mean it could be dark, the weather could be wrong (though that's a decent time of year for the weather in that area), etc etc. Just trying to figure out if the degree of course variation those boats display makes it possible to get them in sight. And I get a few tries at it, there's what, half a dozen of them or more. (If none have run aground or broken masts by that stage.)

Matt
__________________
Refitting… again.
GILow is offline   Reply With Quote
Old 16-10-2017, 03:15   #2
Moderator and Certifiable Refitter
 
Wotname's Avatar

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 20,242
Re: Navigation challenge - hitting a bullet with a snail?

Quote:
Originally Posted by GILow View Post
OK, this may become one of my silliest posts yet... but please, hear me out.

This summer (December in the Southern Hemisphere), the Volvo Ocean Race boats will sail from Cape Town to my old home town, Melbourne.

Let me tell you, as a Melbourne boy, born and raised... I have no idea why they are sailing to Melbourne. But they are. They probably have a good reason.

Anyway, I will be in Adelaide as they sail past to the South of me, and I am wondering if it would be possible to sail out there into Bass Straight and actually watch them sail past. As in, get them in sight at least.

Initially I thought "Not a chance." I mean my boat does 6 knots on a good day, and those things are doing 25 or more.

But... then... I only have to sail North/South, to intercept them... and their location and course are pretty well known in near real time.

What do you navigator types think? Possible?

Oh, and I already know the idea is totally silly, so no need to point that out. I mean it could be dark, the weather could be wrong (though that's a decent time of year for the weather in that area), etc etc. Just trying to figure out if the degree of course variation those boats display makes it possible to get them in sight. And I get a few tries at it, there's what, half a dozen of them or more. (If none have run aground or broken masts by that stage.)

Matt
Well if you are going as far as Bass Strait, jill around Cape Otway and you are sure see a couple of them; if not, nip up to Point Lonsdale.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is online now   Reply With Quote
Old 16-10-2017, 03:17   #3
Registered User
 
GILow's Avatar

Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,112
Re: Navigation challenge - hitting a bullet with a snail?

Quote:
Originally Posted by Wotname View Post
Well if you are going as far as Bass Strait, jill around Cape Otway and you are sure see a couple of them; if not, nip up to Point Lonsdale.
Yeah, getting a bit close to Melbourne for my taste. I am currently stuck here in Melbourne, have been for a while. Totally can't wait to get home. Certainly not keen to sail back.

I made the mistake of smiling at dad's neighbour today. I swear she looked at me like I was about to expose myself and I am sure she was reaching for the pepper spray. I ran back inside the house and hid for a while.
__________________
Refitting… again.
GILow is offline   Reply With Quote
Old 16-10-2017, 03:18   #4
Registered User
 
GILow's Avatar

Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,112
Re: Navigation challenge - hitting a bullet with a snail?

Quote:
Originally Posted by Wotname View Post
Well if you are going as far as Bass Strait, jill around Cape Otway and you are sure see a couple of them; if not, nip up to Point Lonsdale.
More importantly, there'd be something really special about seeing them out in the open ocean.
__________________
Refitting… again.
GILow is offline   Reply With Quote
Old 16-10-2017, 03:20   #5
Registered User
 
GILow's Avatar

Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,112
Re: Navigation challenge - hitting a bullet with a snail?

If they are navigating the Rip, I wonder if they'll wait for the tides...
__________________
Refitting… again.
GILow is offline   Reply With Quote
Old 16-10-2017, 08:54   #6
Registered User

Join Date: Sep 2014
Location: Manila, California
Boat: Cape George pilothouse 36 and a Cape Dory 25
Posts: 608
Re: Navigation challenge - hitting a bullet with a snail?

Just your brand of boat pretty much guarantees success.
fatherchronica is offline   Reply With Quote
Old 16-10-2017, 09:09   #7
Registered User

Join Date: Feb 2014
Location: richards Bay, South Africa
Boat: voyage Mayotte 50 ft cat
Posts: 165
Re: Navigation challenge - hitting a bullet with a snail?

Not a silly idea at all. There is an enjoyable interception navigational calculation that you can do to intercept them. You require their track and speed as well as your starting point and speed. The arc will give you an exact intersection point. see OIC-NW Reviewer Blog: Course To Intercept Vessel

Regards
YPSILANTI is offline   Reply With Quote
Old 16-10-2017, 09:14   #8
Registered User
 
Suijin's Avatar

Join Date: Feb 2013
Location: Bumping around the Caribbean
Boat: Valiant 40
Posts: 4,625
Re: Navigation challenge - hitting a bullet with a snail?

How long will it take you to reach an intercept point? Their track and ETA will be relatively easy to forecast given the accuracy of the tracker; put that together with a weather forecast and it comes down to whether you want to go or not and how long you need to leave in order to get there. Yes you may be bobbing around for a few hours but if it's daylight and the weather is acceptable then it all comes down to whether it's worth the trouble to you. Would be interesting for sure.
Suijin is offline   Reply With Quote
Old 16-10-2017, 10:42   #9
Registered User

Join Date: Mar 2011
Location: fl- various marinas
Boat: morgan O/I 33' sloop
Posts: 1,447
Re: Navigation challenge - hitting a bullet with a snail?

It's not rocket science. Pick the closest point that is on their course. Calculate when they will reach it. Using the distance to the selected interception point and your average speed calculate a departure time. Subtract a few hours for errors and you have your departure time, course and speed.
Dave22q is offline   Reply With Quote
Old 16-10-2017, 11:00   #10
Registered User

Join Date: Mar 2007
Location: Santa Cruz
Boat: SAnta Cruz 27
Posts: 6,683
Re: Navigation challenge - hitting a bullet with a snail?

I'm pretty sure the racers are going to be broadcasting AIS, which should simplify the intercept.
donradcliffe is offline   Reply With Quote
Old 16-10-2017, 11:19   #11
Registered User
 
GILow's Avatar

Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,112
Re: Navigation challenge - hitting a bullet with a snail?

Well, nobody thinks I'm mad, or they are too polite to say so, which is nice.

But, watching these boats I am just no so sure about the whole course thing. They seem to weave about a bit. Sure their overall course is reasonably steady but is it really likely I can get within a half mile of them, which I think would be the maximum distance you'd want to make it worthwhile.
__________________
Refitting… again.
GILow is offline   Reply With Quote
Old 16-10-2017, 11:20   #12
Registered User
 
GILow's Avatar

Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,112
Re: Navigation challenge - hitting a bullet with a snail?

Quote:
Originally Posted by YPSILANTI View Post
Not a silly idea at all. There is an enjoyable interception navigational calculation that you can do to intercept them. You require their track and speed as well as your starting point and speed. The arc will give you an exact intersection point. see OIC-NW Reviewer Blog: Course To Intercept Vessel



Regards


Good stuff!
__________________
Refitting… again.
GILow is offline   Reply With Quote
Old 16-10-2017, 14:41   #13
Registered User

Join Date: Dec 2012
Location: Mannum, Australia
Boat: Houseboat, 60ft.
Posts: 290
Re: Navigation challenge - hitting a bullet with a snail?

Pretty sure most sail a long way South, go below tassie & head up the East coast to Sydney. Not sure about destination Melbourne though.
I know Jessica Watson went way South so there was much less chance of hitting ships at night on auto pilot.
Might be more favourable winds more South too perhaps?
BruceS is offline   Reply With Quote
Old 16-10-2017, 14:50   #14
Moderator
 
JPA Cate's Avatar

Join Date: Nov 2011
Location: aboard, cruising in Australia
Boat: Sayer 46' Solent rig sloop
Posts: 28,400
Re: Navigation challenge - hitting a bullet with a snail?

Quote:
Originally Posted by GILow View Post
If they are navigating the Rip, I wonder if they'll wait for the tides...
Depends where the finish line for the leg is located, and that's probably on their website.

Anyhow, I don't think pepper spray is legal in Oz. Instant antipathy is hard to take.

Ann
__________________
Who scorns the calm has forgotten the storm.
JPA Cate is offline   Reply With Quote
Old 16-10-2017, 15:15   #15
Registered User
 
GILow's Avatar

Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,112
Re: Navigation challenge - hitting a bullet with a snail?

They are going to stop over in Melbourne so that means they'll go North of Tassie unless all the navigators trained on Vestas Wind. :^)
__________________
Refitting… again.
GILow is offline   Reply With Quote
Reply

Tags
navigation

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
SnAIL The Rookie Meets & Greets 4 27-03-2012 11:32
What about Snail Mail ? How do you deal with it when Cruising ? Alecadi Liveaboard's Forum 16 26-01-2012 15:04
About Snail Mail??? Yachts66 Liveaboard's Forum 3 07-10-2005 10:56
Eggs & Snail-Mail GordMay Cooking and Provisioning: Food & Drink 0 30-06-2005 11:16

Advertise Here


All times are GMT -7. The time now is 03:51.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.