Solent question.

[Allan]

Many years ago I first read the some of the special rules in the Solent. Reading the current threads about the Atalana incident has made me think.
When a ship is travelling in a straight line obviously the 1000m and 100m zones are in front and down the sides. When the ship turns what happens to the zone? Does the zone curve around or does it stay as a rectangle?
Allan

 

[alant]

Many years ago I first read the some of the special rules in the Solent. Reading the current threads about the Atalana incident has made me think.
When a ship is travelling in a straight line obviously the 1000m and 100m zones are in front and down the sides. When the ship turns what happens to the zone? Does the zone curve around or does it stay as a rectangle?
Allan

Have a look at a Solent Chart, these areas are clearly marked.

 

[Tranona]

Many years ago I first read the some of the special rules in the Solent. Reading the current threads about the Atalana incident has made me think.
When a ship is travelling in a straight line obviously the 1000m and 100m zones are in front and down the sides. When the ship turns what happens to the zone? Does the zone curve around or does it stay as a rectangle?
Allan

It follows the track of the ship, but is always a rectangle relative to the ship. So another vessel can be stationary and outside the zone at one point in time and inside at another as the zone moves with the ship.

 

[Allan]

Have a look at a Solent Chart, these areas are clearly marked.

No, it's the moving zones I am thinking of.
I assume from Tranona's answer that the centre of the front edge of the zone is 1000m further along the ship's course not 1000m directly ahead of the ship.
Allan

 

[VicS]

No, it's the moving zones I am thinking of.
I assume from Tranona's answer that the centre of the front edge of the zone is 1000m further along the ship's course not 1000m directly ahead of the ship.
Allan

Yachtsman's Guide to Southampton Water and its approaches at http://www.southamptonvts.co.uk/admin/content/files/PDF_Downloads/yachtsman guide.pdf

It just states that there is a mpz 1000m ahead and 100m either side of vessels over 150m. No suggestion that this is relative to the course, just to the vessel

From the Byelaws

Moving Prohibited Zone.
11.(1). In this byelaw -
‘’the Precautionary Area” means the main navigable channel which lies between an imaginary line drawn between Prince Consort and South Bramble Buoys and an imaginary line drawn between Black Jack and Hook Buoys;
‘’Moving Prohibited Zone’’ means an area extending 1000 metres ahead and 100 metres either side of any vessel of over 150 metres length overall while it is navigating within the Precautionary Area.
(2) The master of a small vessel shall ensure that the vessel does not enter a Moving Prohibited Zone.
(3) For the purpose of indicating the presence of the Moving Prohibited Zone the master of any vessel of over 150 metres length overall shall display on the vessel, where it can best be seen, by day, a black cylinder, and, by night, 3 all round red lights in a vertical line.
6​

 

[prv]

I assume from Tranona's answer that the centre of the front edge of the zone is 1000m further along the ship's course not 1000m directly ahead of the ship.

My understanding is that it is 1000m in front of the ship, always a rectangle. Think of it as if the ship had headlights with a 1000m throw, the beam sweeps across as it turns like a car driving down a twisty lane.

Where part of the box crosses the boundary out of the area of concern, I think it gets cut off at that point. In any case if you're outside of the channel you're generally ok in practice, as the ship would need wheels to come and get you!

Pete

 

[jac]

My understanding is that it is 1000m in front of the ship, always a rectangle. Think of it as if the ship had headlights with a 1000m throw, the beam sweeps across as it turns like a car driving down a twisty lane.

Where part of the box crosses the boundary out of the area of concern, I think it gets cut off at that point. In any case if you're outside of the channel you're generally ok in practice, as the ship would need wheels to come and get you!

Pete

Exactly my understanding. Always take the edge of the channel around there and let the shallows prevent the collisions!

 

[zambant]

Exactly my understanding. Always take the edge of the channel around there and let the shallows prevent the collisions!

+1

 

[l'escargot]

Exactly my understanding. Always take the edge of the channel around there and let the shallows prevent the collisions!

You're going to have to cross it at some point...

 

[Allan]

The headlight analogy is a great way to describe it. Now I feel I fully understand. I also agree, staying out of the restricted area is the best idea.
It means that you can be outside the 1000m zone but in the way. Presumably that is one things the safety launch is looking for. Do they ever call vessels and say "look out, there is a danger zone coming your way"?
Allan

 

[prv]

It means that you can be outside the 1000m zone but in the way. Presumably that is one things the safety launch is looking for. Do they ever call vessels and say "look out, there is a danger zone coming your way"?

Yep, that's exactly what they're there for. They come up behind you and politely but forcefully shout at you to get out of the way . I have to admit to having once been so shouted at, many years ago when a group of us first chartered in the Solent. The ship was behind us and we hadn't been keeping a good lookout astern. Still a long way off so there was never any danger, but it was a bit of a surprise!

Would never happen now as I know the place much better and understand the shipping movements.

Pete

 

[Moonshining]

Yep, that's exactly what they're there for. They come up behind you and politely but forcefully shout at you to get out of the way . I have to admit to having once been so shouted at, many years ago when a group of us first chartered in the Solent. The ship was behind us and we hadn't been keeping a good lookout astern. Still a long way off so there was never any danger, but it was a bit of a surprise!

Would never happen now as I know the place much better and understand the shipping movements.

Pete

Yep, I got shouted at once. The ship was heading parallel to us when the patrol boat headed over to us and told us to bugger off. It started it's turn towards Southampton shortly afterwards so we were pleased to get the warning, because we were heading west against wind and tide and weren't really going anywhere at the time.

 

[Resolution]

The headlight analogy is a great way to describe it.

No its not! My car headlights turn with the steering wheel input (like the old Citroen yonks ago).

But it made me ponder again on the difficulty when on the water of judging just how far 1000m is. Perhaps big boats should rig a couple of searchlights or lasers pointing forward, in the style of the Dambusters' bombers, to intersect 1000m in front?

 

[rotrax]

No its not! My car headlights turn with the steering wheel input (like the old Citroen yonks ago).

But it made me ponder again on the difficulty when on the water of judging just how far 1000m is. Perhaps big boats should rig a couple of searchlights or lasers pointing forward, in the style of the Dambusters' bombers, to intersect 1000m in front?

Why go to the bother. If you keep a good lookout, obey any instructions from the launch and keep well clear you wont have trouble.

Southampton VTS is also worth listening to on 12.

If you are caught in the EZ by mischance you wont find yourself in court for being 100 metres inside the zone-unless you hit a big red ship!

 

[Resolution]

Why go to the bother. If you keep a good lookout, obey any instructions from the launch and keep well clear you wont have trouble.

Southampton VTS is also worth listening to on 12.

If you are caught in the EZ by mischance you wont find yourself in court for being 100 metres inside the zone-unless you hit a big red ship!

Perhaps I should have added a smiley to indicate that I wasn't 100% serious......

 

[jac]

You're going to have to cross it at some point...

Practically true but in theory you could skirt round by sticking to the island shore (or heading up Soton Water)

Serious point though that around there in the deep water channel you can end up in the prohibited zone by a ship coming up from behind. (Only been caught out once about 10 years ago) stay outside the deep water channel and you can't.

 

[prv]

Southampton VTS is also worth listening to on 12.

+1 - I always have VTS on the radio when in Southampton Water or the central Solent. After a bit of practice you can have it burbling away in the background and still notice when something relevant comes up.

No moronic radio checks either

Pete

 

[Simondjuk]

As we came round Calshot recently, we were presented with the rather unnerving sight of one of the massive container ships making good speed and pointing right at us. We were perfectly safe as we were only in about 5 metres of water and outside the channel, so not infringing the MPZ, but due to the high winds the bows of the ship were pointing maybe 20 degrees upwind of her track, and her effectively increased width meant she was using absolutely the full width of the fairway. Her bows slid past maybe 50 metres away and she left a muddy wash where she was stirring up the bottom under the shallower water at the edges of the channel. Interesting, if a little disconcerting.

 

[lw395]

As we came round Calshot recently, we were presented with the rather unnerving sight of one of the massive container ships making good speed and pointing right at us. We were perfectly safe as we were only in about 5 metres of water and outside the channel, so not infringing the MPZ, but due to the high winds the bows of the ship were pointing maybe 20 degrees upwind of her track, and her effectively increased width meant she was using absolutely the full width of the fairway. Her bows slid past maybe 50 metres away and she left a muddy wash where she was stirring up the bottom under the shallower water at the edges of the channel. Interesting, if a little disconcerting.

I'm not sure that the MPZ actually cares about the water being too shallow. So you get potty situations where the safest thing to do is to sail into shallow water, but technically it's prohibited.
It will be interesting to see if it is policed any differently next season, now they have a high profile conviction.

 

[alant]

No its not! My car headlights turn with the steering wheel input (like the old Citroen yonks ago).

But it made me ponder again on the difficulty when on the water of judging just how far 1000m is. Perhaps big boats should rig a couple of searchlights or lasers pointing forward, in the style of the Dambusters' bombers, to intersect 1000m in front?

Would they work in bright sunlight?