How do you find a sunk mooring?

[Adrianp 120]

So the mooring I've rented out has sunk in the two weeks between boats

 

So, on Saturday I'm going to find it. Luckly its only about 20m from a channel marker post so we should be able to get to its rough position pretty easily.

 

So then what? Drag an grapple around? Dive aimlessly in the gloom of the Tamaki River? Any suggestions?

 

Can a good depth sounder pick up anything?

 

To help suggestions, its mooring TA068 in this photo:

[Adrianp 120]

Try a bigger version

[banaari 27]

I think I'd try diving, using the boats anchor chain to provide a fixed reference. Maybe tie a line to the anchor and use it to conduct a spiral search?

[Guest]

Been there done that.

From memory as it was a few years ago..

We used a fish finder, a Very basic Grey scale jobbie to locate the block on the bottom. A better more modern one would be even better. This got us close enough to put the diver down and he dragged a large commercial magnet until it latched onto the chain.

 

I think You can adjust the modern Fish finders to hone in on the bottom densities/ texture. This should highlight the dense block in the mud if its not to deep.

 

Take a grapnel too.

[Guest]

Could also check with mooring maintenance contractor. They may have a GPS waypoint for the mooring?

[Guest]

Take a grapnel too.

As that is the driest way and also the very thing contractors use.

[rigger 47]

Grapnel, they work really well.

Work out the most likely directions that it could lie in then run crosses over those.

Once you get a grab do not slack of the tension, keep it on and have a new buoy and several bits of line to secure buoy to mooring.

Is the old buoy still attached?

[Adrianp 120]

Sweet, thanks all for the suggestions.

 

Yes the buoy should still be attached. It was an air filled one that had a little crack in it, so we tied a fender to it, but I guess the whole lot went down. Its in a very tidal part of the Tamaki River so I would expect it all would only be lying just upstream or downstream of the block.

 

We're heading out there tomorrow with a good fishfinder, dive gear and a grapnel, so hopefully we'll find it!

[rigger 47]

Good luck.

Make sure the grapnel is the right size for the job

[Toltec 7]

I would use a grapnel and tow it up and down bound to hook it up also try slack low tide you might find buoy up with no weight on line have had to find a couple of sunk buoys and moorings over the years

[figaro 0]

The same thing happened to me at easter by bbyc. We used the gps to find it then used a grapnel with a chain found it on the second pass.

[Adrianp 120]

Found it! Thanks all for the advice. Apart from having to dive for it (in the Tamaki River at Pamure ), its quite an enjoyable way to spend an sunny, still, afternoon

 

Used a grapnel which we dragged back and forth slowly working into the tide. When we hook onto it, we couldn't haul anything up, so sent a diver down, who found we had hooked the chain only two links from the train wheels!

[Guest]

Good news.

 

Thought that would happen. That's why i suggested diving first as that happens all the time.

 

The chances of picking up the end of the chain (the bit you need to drag up to the boat) is less than the middle ( which will not reach the surface)