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18-12-2008, 14:57
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#151
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Registered User
Join Date: Mar 2006
Location: West Palm Beach, Florida
Boat: Gulfstar 44 Sloop
Posts: 648
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Quote:
Originally Posted by jcknox
This may be a little of topic but would it be possible to mount a depth transducer horizontally at the bow. In effect creating a forward looking sonar to detect submerged objects? Would this work?
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There are several makes of forward-looking sonar (depth sounders) for small boats. They don't have much range, though.
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Starfish
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18-12-2008, 16:07
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#152
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Registered User
Join Date: Nov 2008
Location: Lincolnshire UK
Boat: Mac 26x
Posts: 169
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so how good is small ships radar? will it pick up all boats with radar deflectors at say 4nm?
i think that the ballance is to be rested and alert,running on a sleep pattern that in the end equates to sleep deprevation is possibly more dangerous than actually sleeping through a near miss and should the weather kick up into a situation where you need to be awake for 72 hours,you surely have to remain rested during a long passage and with enough in the tank to handle a storm
or could colregs accept a stobe light of some sort that ould be used to indicate that the skipper was having a nap or a transponder arrangement
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18-12-2008, 16:56
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#153
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Registered User
Join Date: Dec 2004
Location: Vancouver BC
Posts: 1,385
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Okay, how about 'sleeping while singlehanded is useful, since if you don't you die. Keeping watch is useful, since if you don't you might get run down, but less likely than you'll run into the crunchy bits around the edges of the safe blue water.' Does that suit the thread? : :
__________________
Amgine
On the internet, nobody knows you're a dog anchored in a coral atoll.
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18-12-2008, 17:08
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#154
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Registered User
Join Date: May 2008
Location: British Columbia, Mexico
Boat: S&S Hughes 38
Posts: 837
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When Im close to land I definitely wont be sleeping.When I said "in daytime others can see you easier",Im thinking of smaller boats,who dont have AIS transponders,(or bright lights at night) For bigger ships I will be watching out for them and receiving an AIS alarm to alert me to alter course.Ideally ,15 minute horizon scans would be the goal.Also agree about being awoken abruptly in the dark as opposed the daylight.
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18-12-2008, 17:24
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#155
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Registered User
Join Date: Oct 2007
Location: Southern California
Boat: Was - Passport 45 Ketch
Posts: 888
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Quote:
Originally Posted by highseas
When Im close to land I definitely wont be sleeping.When I said "in daytime others can see you easier",Im thinking of smaller boats,who dont have AIS transponders,(or bright lights at night) For bigger ships I will be watching out for them and receiving an AIS alarm to alert me to alter course.Ideally ,15 minute horizon scans would be the goal.Also agree about being awoken abruptly in the dark as opposed the daylight.
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You might want to consider 10 minute intervals. 15 minutes is quite marginal. That's about the time that it takes a vessel to come up over the horizon and reach your position at 20kts. 20kts is a very common cruising speed for commercial ships.
In my time of over 100,000 miles at sea, I have come across 2 yachts, beyond 100 miles from shore. One of those yachts was on purpose as I hove-too for 3 days to transfer food to starving cruisers, 600 miles off of Mexico, en-route to San Diego from Galapagos Islands.
I have a cute (on-topic) side story that I would like to relay at this point.
I have a friend that was an engineer on a 75' fishing vessel. One time they were cruising along looking for tuna about 200 miles off the Mexico coast. They saw a yacht off in the distance and changed coarse to check it out. As they approached the becalmed vessel, it was clear that there was no one on deck. To be sure that everything was OK, they slowed and pulled up to the yacht. Laying in the cockpit was a sleeping, single-handed sailor. As a joke, they got an ice cold bottle of milk, lowered it down on a line and left it in the cockpit, next to the sleeping sailor. They then quietly motored away.
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18-12-2008, 17:34
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#156
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Registered User
Join Date: Jul 2007
Location: W Florida
Boat: Still have the 33yo Jon boat. But now a CATAMARAN. Nice little 18' Bay Cat.
Posts: 7,083
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Quote:
Originally Posted by Kanani
. As a joke, they got an ice cold bottle of milk, lowered it down on a line and left it in the cockpit, next to the sleeping sailor. They then quietly motored away. 
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OMFG......
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18-12-2008, 17:38
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#157
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Registered User
Join Date: Oct 2007
Location: Southern California
Boat: Was - Passport 45 Ketch
Posts: 888
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That was in '88......so...... if that sailor is now at home reading this forum.........that's where that bottle of milk came from.
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18-12-2008, 17:43
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#158
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Moderator Emeritus

Join Date: May 2007
Location: Ohio
Boat: Now boatless :-(
Posts: 11,580
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Quote:
Originally Posted by Kanani
I'm not saying that they would intentionally run you down, I am just saying that your chances of being seen by a ship is slim to none, day or night.
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In the 66 Days Adrift book the couple spotted ships a couple of times. I think they even had a flare left for one of them and shot it off. Must have been horrific to be at sea in a 4 man raft for almost 2 months and see a ship motoring away.
You are spot on - they don't look.
Which begs the question. What's worse, a ship with no one on watch except a radar or a sailing vessel with no one on watch except a radar?
Quote:
Originally Posted by Kanani
Laying in the cockpit was a sleeping, single-handed sailor. As a joke, they got an ice cold bottle of milk, lowered it down on a line and left it in the cockpit, next to the sleeping sailor. They then quietly motored away. 
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That's a pretty tall tale. We have +40' motor launches that do immigration at sea here. They periodically bump our boat when handing passports into a fishing net on a 5 foot pole in 3 foot swells and 7 knots wind. I couldn't imagine them getting close enough to lower a bottle of milk on a string. Oh, and the engine sounds like a freight train.
Musta been one exhausted sailor...
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18-12-2008, 17:56
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#159
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Registered User
Join Date: Oct 2007
Location: Southern California
Boat: Was - Passport 45 Ketch
Posts: 888
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Quote:
Originally Posted by Ex-Calif
In the 66 Days Adrift book the couple spotted ships a couple of times. I think they even had a flare left for one of them and shot it off. Must have been horrific to be at sea in a 4 man raft for almost 2 months and see a ship motoring away.
You are spot on - they don't look.
Which begs the question. What's worse, a ship with no one on watch except a radar or a sailing vessel with no one on watch except a radar?
That's a pretty tall tale. We have +40' motor launches that do immigration at sea here. They periodically bump our boat when handing passports into a fishing net on a 5 foot pole in 3 foot swells and 7 knots wind. I couldn't imagine them getting close enough to lower a bottle of milk on a string. Oh, and the engine sounds like a freight train.
Musta been one exhausted sailor...
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You got the story the way that I got it. BTW....I was on board the fishing boat and the fishing boat's captain was there when he told me the story.........he did say that it was flat calm. I asked the same question....how could the engines not wake the guy? He said that they just idled off for awhile.
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18-12-2008, 19:03
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#160
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cruiser
Join Date: Mar 2004
Posts: 1,167
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Mt steel hull makes striking things at sea a much less significant threat.
Brent
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19-12-2008, 04:26
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#161
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Registered User
Join Date: Nov 2008
Location: Lincolnshire UK
Boat: Mac 26x
Posts: 169
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hahahaha what must have gone through that guys head when he woke up,wonder if he got up the next morning expecting a delivery from the local milk man
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19-12-2008, 06:34
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#162
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Registered User
Join Date: Nov 2005
Location: At the intersection of here & there
Boat: 47' Olympic Adventure
Posts: 4,892
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Quote:
Originally Posted by bastonjock
so how good is small ships radar? will it pick up all boats with radar deflectors at say 4nm?
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MAIB commissioned a study on radar reflectors, here: http://www.maib.gov.uk/cms_resources...s%20report.pdf
Even if you use the best and have it optimally set, you still have to trust the other party has their radar operating, tuned correctly, and monitored.
Quote:
or could colregs accept a stobe light of some sort that ould be used to indicate that the skipper was having a nap or a transponder arrangement
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In some jurisdictions, a strobe light is an emergency signal - so instead of warding off other vessels, it may bring them closer. Others have suggested lighting as Not-under-command or Restricted-in-ability-to-manoeuvre, but the colregs still require those vessels to maintain a lookout, so no guarantees there. I would never plan to single-hand where I would need to sleep - if injury/illness forced it upon me, I would drift on a sea-anchor, with NUC signals, AIS and radar on with guard alarms, VHF turned up to max volume.
Kevin
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19-12-2008, 08:38
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#163
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CF Adviser Moderator Emeritus

Join Date: Sep 2007
Location: Virginia
Boat: Island Packet 380, now sold
Posts: 8,943
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Quote:
Originally Posted by bastonjock
so how good is small ships radar? will it pick up all boats with radar deflectors at say 4nm?...
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I have two Mobri reflectors on the shrouds above the spreaders. Ships that were willing to answer me say they can see me from 5-6 nm out.
__________________
Hud
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19-12-2008, 10:03
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#164
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Registered User
Join Date: Oct 2007
Location: virginia
Boat: islandpacket
Posts: 1,973
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This just in. Dead sailor found with a cold bottle of milk. Coast Guard confused as to events. Searching for boat seen leaving scene without reporting.
__________________
That derelict boat was another dream for somebody else, don't let it be your nightmare and a waste of your life.
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19-12-2008, 16:46
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#165
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cruiser
Join Date: Mar 2004
Posts: 1,167
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A ship is far more likely to sink someone than the average sailing yacht. I've never heard of a freighter being sunk by a yacht.
Brent
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