Friday, March 3, 2023

2023 March 3rd - Preparing for the scrub and a shout out to "Total Tide"

The RAFYC maintenance dock is a very economic alternative to a lift out for a pre-season scrub and touch up of the anti-fouling, Sancerre had 3 coats a year ago and another in July so should be OK for this season but the boot line was changed in July so an extra coat on that seems sensible and perhaps another coat of blue if it looks thin and time permits. 

The dock is equipped with an industrial standard power washer so once the tide has dropped the clean does not take long, but you do have to be careful not to take off the anti-foul by getting too close.

The RAFYC maintenance docks (© RAFYC). Getting in is
reasonably straightforward, getting out trickier as there is
little room between the RAFYC launches on the pontoon and
boats in the marina and Sancerre does not steer that well going
slow astern, but there is good protection from the tide much of
the way so I can warp her through the narrow part if necessary.
An early start is required to enable me to be in and out in one tide, to use the full 24 hours I would need to be there as she lifted on the second tide and settled on the following ebb - and I could not reasonably stay on board. 

The dock sill is at 2m above datum and Sancerre draws 1.7 metres so I need close to 4 metres to get in and out safely allowing for a lower than predicted tide if there is particularly high atmospheric pressure and / or a NE wind. That is not available at neaps so I went for the 13th March, four days before the neap tide, far enough away to avoid being "neaped" (Having sufficient water on one tide but insufficient on the next to get out or off) but close enough that I would have enough daylight for the scrub, replacing the anodes and any touch up work.

The days tide as shown by Admiralty "Total Tide", many
apps do not show the curve for the Hamble accurately, particularly
the 2nd high, often shown as a simple "stand" or not at all and
the "Young Flood Stand" starting c 2.5 hours after low water.
I need dead slack water or an incoming tide to get on and off the mooring so going into the dock at 04:30 gives a few hours sleep and, even allowing for any depressed height, sufficient water to get in on the second high and plenty of water on the first high at at 14:00 to get out of the dock.

Admiralty "Total Tide" vs the rest.

It's interesting to compare this prediction from Imray's Tides App (and
 most other apps) with the "Gold Standard" the Admiralty's "Total
Tide" shown above it, the later is expensive but far more detailed in
complex situations you find around the Solent, Poole etc.

Total Tide will do a lot more and to a very fine resolution, of
course wind and atmospheric pressure will impact the above
but its a very good starting point. Unfortunately it only runs
on a PC.
And tidal streams as well - more than shown on the charts, here
the Portland inshore route is just opening on March 17th although
 at the time of writing it looks like the weather will not be good
enough to leave that week.
Update March 7th: With a couple of exceptions the weather models have started to come together and there is a good chance of 20 - 40 knots of wind along the south coast early next week, too much to safely get off of the piles and onto the mooring single handed and I have no desire to beat against a strong south westerly to go sailing so I have booked the piles for another day on Monday the 27th and if the weather is reasonable I'll be looking to leave on the following Wednesday to go round the Portland inshore route on Friday 31st.

If I am able to get on and off the piles next week I will do so and perhaps come out a second time on the 27th to put a full coat of anti-foul on.

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