Arwen's meanderings

Hi everyone and welcome to my dinghy cruising blog about my John Welsford designed 'navigator' named Arwen. Built over three years, Arwen was launched in August 2007. She is a standing lug yawl 14' 6" in length. This blog records our dinghy cruising voyages together around the coastal waters of SW England.
Arwen has an associated YouTube channel so visit to find our most recent cruises and click subscribe.
On this blog you will find posts about dinghy cruising locations, accounts of our voyages, maintenance tips and 'How to's' ranging from rigging standing lug sails and building galley boxes to using 'anchor buddies' and creating 'pilotage notes'. I hope you find something that inspires you to get out on the water in your boat. Drop us a comment and happy sailing.
Steve and Arwen

Monday, 31 May 2010

My first passage plan......let's hope it works!

Well here we go - my first passage plan......this could be interesting.

I intend sailing this Wednesday June 2nd. I'll leave Queen Anne's battery and motor out to South Mallard buoy for 10.30am departure. 

Where I always launch from - the southern slip (on the left!) at QAB
The big glass building on the right is the National Marine Aquarium
In the background is the famous Barbican

I'll head out past the west end of the breakwater up to the Knap buoy before swinging east towards West Tinker buoy. Then I'll head north to the eastern end of the breakwater, up to the Duke buoy and back to where I started at South Mallard. Its 6 NM.

The western end of the Plymouth Breakwater copyright Michel LaLonde

The weather is predicted Force 2/3, from north west...sunny with odd cloud and temp around 19 Celsius. Visibility is good and sea state slight.

Wednesday's weather forecast: source BBC/Met Office

I should be on a beam reach/training run for the outward leg; from Knap to West Tinker it should be a downwind run before turning onto a close haul run back to port........I think......if my visualisation is right!  Now whether this is the right way around to do this route.......or not...... I have no idea. If anyone knows better.......please let me know before Wednesday!

My passage plan template
I combined two or three to get what I wanted

High tide is at 9.45am - 4.9m falling to 1.7m at low tide (so the tidal range is 3.2m if my maths is correct....and that's a BIG if!). It's an outgoing tide, with low tide at 16.04. The tidal stream according to the tidal diamonds is negligible for first two hours on outgoing tide. However, on the close haul from east breakwater back up to Mounbatten - there is a 1 kt tidal stream running 171 degreeM - so against me - so that will affect my progress northwards. I think I will be averaging 3 knts so on this leg I'll drop to 2 knts.

I managed to work out how to use them - brill!

Dead reckoning suggests I should do 6NM at 3 kts in 2hrs. So my ETA back at South Mallard should be around 12.30pm.  However, when I take into account the tidal stream then it will be around 12.45 ish.

I've marked the route on the chart using the conventional symbols; I've also worked out the magnetic bearing, distance and dead reckoning time between each buoy. I've entered them as waypoints in my GPS and I've created a route ready for Wednesday. I'm slightly panicky that I've got my latitude and longitude reading off the chart scales wrong. I'm OK at say N50d 20'....its then getting the end bit!

A page from my Admiralty Tough Chart showing Plymouth Sound north of Breakwater
Area 13: Plymouth Sound and rivers     1st edition SC 5913
Published by Admiralty Leisure

I printed off a passage plan and sealed it into a clear plastic wallet which I can now write over the top of in chinagraph pencil - a perfect re-useable passage plan framework.  I've also taken the precaution of sketching out annotated diagrams on how to pick up moorings/leave moorings under sail etc and I've taped them into another clear plastic wallet.

The reverse side of my passage plan

I now feel ready! I'll check the forecast again tomorrow; and go over the calculations again. Of course.....I'm stuffed if I average 4 or 5 kts....I'll have to redo the maths on the go........never a good thing given my non maths ability!  So I've taken the liberty of copying the ready reckoner from that book I recommended on a previous post.....

from Sea Kayak Navigation by Franco Ferrerro....see a previoug for further details
Of course if you do above 4'll have to work one out for youself!


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