Tuesday, September 6, 2022

2022 Celtic Circuit, Day 31 - 34 Stuck in the Truro River

 The weather and the forecast remain pretty awful.

Rainstorm on Monday the 5th, just after the thunder and lightning had passed.
Wind was forecast to be gusting in excess of 40 knots but it was not quite that
strong in the sheltered Truro River. Its much the same as I write.

At the time of writing (Tuesday morning, day 31) strong winds and rain are forecast to persist until at least Friday with thunderstorms today and tomorrow - it is tipping down at the moment in a thunder storm and I would need a light on to read. Not as bad as the last few days but bad enough with the ECMWF & UKMO models showing gusts of 30 knots or more every day and the American GFS slightly less (unusual over the last couple of weeks) but still over 25 knots. Winds on Saturday looks OK but seas, forecast to be rough or very rough over the next coupe of days, will take some time to moderate. Then to rub salt in the wounds there may be easterly head winds.

So, I am here for a while, the pontoon is costing £18 per day, is secure and in deep water (the pontoon is attached to two large buoys that in days gone by were used for large mothballed ships) but the only facility provided is rubbish disposal which I could still use if at anchor close by. So I thought to move to the anchorage.

The anchorage below maggoty Bank, the harbour masters launch
right coming down for money. Annoyingly I now find a 10 day ticket
is available for the price of 8 individual days. 
 The shallow areas were last
surveyed 25 years ago so may
not be accurate,
Whilst restoring the bunk to be used for seating I got out one of my 10 Kg kedge anchors that was in the locker under and set it up ready to back up the bower anchor (I run it down the chain on a carabiner to help keep the pull on the anchor near horizontal and to provide additional weight, there is a long piece on anchoring I wrote for the Achilles site here).

Then did what I should have done first, checking the tide tables.

It turns out that this weekend has particularly big spring tides, with low water down to only 10cm above the Lowest Astronomical Tide (LAT), that restricts the area available to anchor a boat drawing 1.7 metres. Check the section of chart to the right, the actual depths at low water will be close to those shown before allowing for waves and wash which means I would have to be in the section with depths shown as 3.4m and 3.6m, as are the boats in the picture above.

To anchor there in a strong wind and tide I would need to let out a lot of chain. At least four times the maximum depth is recommended which equals 4 x (5.5m [rise in tide] + 3.4 [depth at LW] + freeboard) = c 40 metres.

That introduces another problem, with all my 42 metres of chain out (the next 40 metres of the rode is nylon), at low water the boat could swing at least 35 metres in any direction with the keel about 5 metres beyond that; that could take me onto a drying bank. 

The obvious answer would be to anchor fore and aft using my back up bower / #1 Kedge, a 24 Lb CQR with 5 metres of chain and 80 metres of 14mm nylon and I should be secure enough and although I had the dinghy out it could be done from the boat by dropping back the full length of my 80 metres of chain and nylon on the Bower before dropping the stern anchor and then hauling forward; but getting the kedge up later would be a pain in the back and if one anchor did drag at low water I could quickly be aground so I decided against that.

There is more room to anchor further upriver but there were some boats there a couple of days ago and similar issues may well apply, and I could loose my place on the pontoon so I'll pay up with gritted teeth and stay here.

The pontoon just about filled, "Maybe" the large Gaff Cutter was anchored in
the anchorage discussed above the day before yesterday but overnight dragged
her anchor and ended up on Maggoty Bank floating off yesterday morning.
I boat like that is not going to come to any harm there, the same may not apply
to a fin keeled yacht stranded on the bank would be on it is side, and if on an
adverse slope might flood when the tide came in.

I imagine the crew are even less happy with the weather than me - they have paid
£1.5k for a seven day cruise to the Isles of Scilly and are stuck here for most of it
with no refund as the itinerary is weather dependant.
On to St Mawes.

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