A foggy day

[Antares_9]

In Shotley Town. After a glorious day and evening out we stayed out anchored up with a view to doing the two or so miles back to Shotley early Sunday and catch “free flowâ€. When we woke the vis. Was so bad you could hardly see the bow from the wheelhouse so we decided to wait, and wait, at around 50yds vis. we got under way. Thank goodness for Mr Raymarine, the Chart & radar overlay made the trip a lot less stressful than it would have otherwise have been with so many other vessels and obstructions around. Perry and Tina were close behind aboard Kiki and just visible in the “murkâ€. When we arrive at the channel posts for the marina it was impossible to see ¼ way down the dredged channel and I have never been so glad to see those lock gates even if we nearly hit them before we saw them.

[Guest]

Sounds like fun. I seem to remember navigating down the river in conditions like that (or worse!) once before. Sadly that was before our GPS plotter was installed. Having our previous GPS tracks would have been a massive advantage at that time. Of course, once it was fitted we never saw fog again - plenty of rain but no more fog.

[pks1702]

Mr Raymarine earned his corn alright

I zoomed the channel to its maximum size on my plotter and trusted to this rather than just my eyes on our entry to this not overly wide channel. It was incredible that we could not see the lock gates until within around 50 yds, the plotter and kit certainly did its job.

The only saving grace was that it was just after HW so there was enough under the keel even if we did wander off channel. At LW in a yacht drawing 7 feet would have been mighty interesting

[pks1702]

Nav aids are no substitute for good seamanship.

Quite right Rod..... but they help :-D

It was as it is sometimes; at the Orwell Bridge it was bright sunshine

[Antares_9]

Nav aids are no substitute for good seamanship.Rod

Absolutely agree Rod, but without them "good seamanship" would have meant staying where we were, unfortunately my best nav aid (MK1 eyeball) was not functioning too well :-D :-D

The thing that really gave me confidence was that when overlaid on the chart plotter and a gyro stabilised heading sensor keeping it all synchronised, the “real time†info from the radar corresponded so accurately with the chart, returns from nav buoys were on the buoys on the chart or right next to them even at high zoom. Interesting that some vessels even with radar reflectors didn’t “show†whilst others without did and even the moored lightships gave quite a small return. Goodness knows what we would have done if it had all gone down, gone back to somebody on the bow with a fog horn, got the paper charts out and proceeded on compass and sounder at crawl ahead I guess, or found a shallow bit, dropped the hook and had beer.

[pks1702]

In restricted visibility give the 'big stuff' a wide berth and as much as possible stay clear of the shippling lanes

Good rule of thumb in any conditions Rod, keep from under big stuff's feet.

We ran outside the Channel which allowed us a view of the buoy we expected from the plotter to confirm our position. With the depth under us at times I doubt any big stuff would have ploughed a furrow too far before coming to a halt

There certainly did not appear much big stuff moveming in the fog from what I could see

About as good as it got:

viewtopic.php?f=37&t=2948&start=70

[senator]

Frightens the life out of me, have to get the radar working on Clandestine, think it is just an electrical supply fault but been busy getting the other bits working up untill now.

What worries me more is how much trust can you put in a radar that was not working when you bought the boat and you do not know how it has been fitted.

Have even contemplated taking it completly out and refitting it from scratch GPS has simlar issues in that I can turn it on but have to disconect the wire to turn it off, dare'nt even try the auto pilot.

run a seperate laptop for Chart plotter, linked to a seperate GPS unit.

When you are trusting nav aids with your life how far do you go when you only use the boat at sea occasionally?

[Antares_9]

When you are trusting nav aids with your life how far do you go when you only use the boat at sea occasionally?

The same distance as you would if using it every day Ian, and use frequently to test it even if only on the rivers, I like your idea of removing it all and installing it all again with new cabling, probably what I would do under the circumstances :-D

[pks1702]

What price life Ian?

Either that or you have to be very confident of your chart and compass work including allowance for drift, tides etc particularly around a region with drying banks and shoals.

A good sounder is your get out of jail card in terms of avoiding running aground but it is amazing how disorientating it can be at sea where it is just like snow blindness.

I managed to pick this one up on the Radar moored 20 yds behind us though

Seriously the Radar really proved its worth yesterday

[senator]

Suppose it is the only sensible answer given the question,

Heard a rumour that an operating radar is a better reflector than the passive radar reflectors, was going to fit a cheapo and use the radar if that were the case. Is this true or is the only answer to fit a seame or simlar?

Ian

[senator]

Thanks Perry, have never used my sounder in anger for navigation, did it in theory for day skipper but would be very worried about it in thick fog, plus unless the cargo ship has already hit the bottom and sunk it is not going to show up to well.

[Antares_9]

You will get many opinions of various reflectors and their use, RNLI say fit one, personally I'd rather have an active transponder like the see me, as I said earlier or in another thread, some boats fitted with reflectors were not "seen" by our radar. My view is i@d rather be in control and be able to see other stuff and act accordingly raher than trust I have been "seen". I can say this, Kiki showed up like a tanker without a reflector, but she was turning her radar.

[Guest]

Thanks Perry, have never used my sounder in anger for navigation

You need to go Oulton Broad more often then. And Surlingham. Oh and Rockland St Mary. I was also going to suggest going outside the posts on Barton Broad but I guess getting there would convert Clandestine from Statesmen to Ambassador!

Seriously though, even messing about south of Lowestoft it pays to keep an eye on the sounder.

[senator]

Hi Simon,

Sounder is always on and monitored but have never overlaid that information against the contours of the charts in order to navigate, if you are good enough with your tidal calcs and keep a close enough eye on your charts then you can effectively follow a contour line like a road, so you know exactly where you are. problem is that it doesnt show you what is on the surface, so in thick fog you know where you are but not where anything else is.

Ian

[Antares_9]

Interesting comment Rod, one for the “Mythbusters†show I guess. Nevertheless we both gave strong returns (abait at close range (say ½ mile max) I wonder if the foil fireproof backing which is present in fair sized sheets on the engine room soundproofing contributed, or indeed the dirty great lumps of cast iron we both have in the engine room. This could be why most decent size motor cruisers seem to give a better return than a WAFI of similar size.

[senator]

Rod,

Given that both David and Perry gave strong returns on each others radar, would that automatically transfer as a strong return to a much larger ship, higher mount and more clutter, or would they just get lost in the rest of the mess?

I have heard this from a few people traveling in company, where despite having a radar reflector fitted they have not been picked up on the other ship prior to switching on their radar, once activated they show up very strongly.

Ian

[Antares_9]

Mmm, next time we're out we can do our own "Mythbusters" experiment by turning them on and off, as far as I'm concerned if Rod says it's so then it's so, he's out there doing it all day most days, and has been doing it for some while now and has the C.V. to back it up

There is however the possibility that because leisure radar and "propper" ship radar being different, then "see" each other differently, more after Adam and Jamie have tried it out.

[Guest]

So which one of you is Adam and which one is Jamie?

[Antares_9]

So which one of you is Adam and which one is Jamie?

It changes Simon, it changes, only the hats remain the same.

[pks1702]

So which one of you is Adam and which one is Jamie?

Have guess who is wearing the hat today

[senator]

Adam/Jamie

will watch for the result with interest but if what Rod is saying is true (same sentiments as David as to Rods knowledge) then you are going to be avoided by the highly manouverable 32 footer who will see you at least 1/2 a mile away but run over by the super tanker. would be great if the mythbusters could get feedback from a proper ships radar somewhere as well.

Ian

[Antares_9]

would be great if the mythbusters could get feedback from a proper ships radar somewhere as well./quote]

Well, if we can find somebody with an X band, maybe one of the pilots who sometimes frquent the Shipwreck we could do that too.

[Antares_9]

This http://www.ussailing.org/safety/Studies/radar_reflector_test.htm makes interesting reading.

[pks1702]

This one is interesting and commissioned by MAIB following the 'Ouzo' yacht tragedy

http://www.maib.gov.uk/cms_resources/Ra ... report.pdf

[Antares_9]

Quite good to think that this thread with all it's input has us all thinking and may even have contributed to making our boating that little bit safer, it may well be interesting to start other threads along similar lines, e.g.. Planning, kit to carry, onboard checks, personal equipment, near misses that could have been avoided. I'll leave it for somebody else to start though.