I’ve found three really useful books – I’m sure there are many more....but these I like.
The first is Sea kayak navigation by Franco Ferrero (published by PESDA PRESS ISBN: 9781906095031).
I like its simple style, informative diagrams and simple end of chapter tasks that help you practice what you’ve just read.
Another one I like and have found easy to understand is Inshore Navigation by Tom Cunliffe Wiley (Nautical Press ISBN 9780470753897). It’s informative, with a nice writing style and good illustrations.
Finally the third one is a useful reference book REED’s Skipper’s Handbook for sail and power (Adlard Cole Nautical ISBN: 9780713683387). It’s just a simple mine of information for when you’ve forgotten what you’ve just learned.
Well I’m about to plan my first passage plan proper for going up the Lynher which I will attempt sometime over the next few weeks. Basic things I’m learning/grappling with:
1. Using the coastline as a handrail; applying what I know about using OS maps – checking off prominent landmarks; orientate the map/chart to follow the coastline as I go along
2. Knowing my chart symbols and get really familiar with them and checking them off as I sail along
3. Getting distance measurements right – I’m having to grapple with new co-ordinate work (lat and long) and nautical miles not kilometres. 1 nautical mile = around 2 km; it’s slightly more than 1 land mile and 1 knot = 1 nautical mile....duh! Then 1 minute of latitude = 1 nautical mile, so 1 degree of lat = 60 nautical miles. Brain is beginning to ache – feeling a Homer Simpson moment approaching - doh!
4. Remembering to measure distance on the chart off the side latitude scale and because of the way charts are drawn – measuring distance using the scale opposite to the point where you are measuring.....ah!
8. A tip I picked up from one book was to draw extra lat and long lines on the chart (I use admiralty tough charts – A3 and waterproof). It helps enormously.
9. I’ve got in my head all about tides, their formation and tide types – semi diurnal etc – useful to know and I’m pretty familiar with using tide tables to get tide times and heights as I did lots of fishing until work took over my life...as it does!
12. I understand tidal range and how to calculate it – I’ve started to better understand tidal heights on charts and the drying out heights. I’ve got to remember that underlined figures and green shading = drying out heights so 5.4m would mean that is the drying height at that point - covered at high water but drying out when sea level reached 5.4m – that point would dry out......at least I think that’s right – may need to check that again! I once had a tiny dinghy I fished from called pugwash......I sort of inherited it partly built and finished it off – a selway fisher highland 12. The number of times I ended up dried out on Salcombe mudflats because I didn’t get those damn drying out tide numbers and calculations right.....so humiliating! Then there is the rule of twelfths....another damn rule! So......in first hr it comes in 1/12th of its range; 2/12ths of its range in second hour; 3/12ths in 3 hr;3/12ths in fourth hour; 2/12ths in fifth hr and 1/12th in last hour. Hmmm! I feel more maths coming on again! Given that Arwen only draws 2’ 6” with centre board down – does it matter? Probably!
13. Time-distance calculations – wow. I know we use them when walking (simple Naismith’s rule stuff); now I’ve got to get my head around another lot........if you know what your average boat speed normally is in certain conditions – then it becomes easier....but I’m not sure I’ve got that kind of information yet from sailing in Arwen – it seems to vary each trip!!!!! Anyway, dividing distance by speed will give me a journey length time (15 miles at 3 knots = 5 hours); on top of which needs to go hoving to for eating, or whatever. Then there is dead reckoning.....so sailing at 6 knots for 30 minutes = a distance of 3 nautical miles. The sea kayaking book had a great idea which I am going to do – a dead reckoning chart which has distance down one side and speed in knots along the other – all the calculations are done so avoiding some mental maths when you are tired and wet – good idea!
14. Confirming your position regularly using fix’s is critical...........sailing around Plymouth sound is dead easy and you can fall into a sense of false security.....I tend to mentally check off where I am etc but rarely worry about speed distance, leeway etc – well that’s going to have to change! Firstly there are the little symbols you draw on the chart – a dot in a circle for an accurate fix; a circle with two bearing lines through it at angles corresponding with bearings fix; a line with a arrow across it for showing water track and course to steer; a line you are moving along with a little dash drawn across at right angles to show dead reckoning position....and so it goes on – there is a complete coded language to learn here!
16. Lights and buoys – no problem – got all them including cardinal marks, lateral marks etc; recognise them on charts and understand the different shapes; beginning to interpret chart codes alongside them regarding the number of flashes etc
18. Chart work – I’m having nightmares here.....real ones..........I see Breton plotters floating before my eyes! Laying off a course is the straight line you put on the chart between the two points you are sailing between. I know how to read a bearing along that line using the Portland plotter – same principle as a mountaineering compass.....no problems there. I now have the true bearing which I turn into a magnetic bearing and this becomes my course to steer. It’s an entire new language to assimilate!!!!!! I struggle to understand English and welsh....never mind sailing jargon!
19. Getting fixes based on bearings......I sort of understand the philosophy and mechanics because its similar to mountaineering in some ways. I take a bearing on a land mark; convert it back to a true bearing; lay it off as a line on the chart. I take another bearing on another landmark as close to 90 degrees angle from the other one as I can and convert and lay that off on chart – where the two lines cross is my fix.............it seems so easy saying it......it seems a little more complicated when I’m hove to trying it out! I hope I don’t need rescuing because i’m slightly confused about this business of telling someone else your position....latitude and longitude – fine; bearing and distance...well is it ‘bearing from eddystone lighthouse is......X at distance of ....Y’ or is it ‘eddystone lighthouse is on bearing X from me at distance of Y’...........um....does it actually matter?
I would like to say that I am well into understanding how to calculate leeway and make allowances for wind and tide on a course but I’d be lying.......at the moment it’s a step too far........I need to internalise all of the above – practice it in next couple of weeks and then perhaps start looking further at passage planning.....I am all new to this you know!
Sorry for the long blog - not a rant you understand.....but a sort of wow - such a high learning curve....I love learning new things...but my poor brain doesn't retain as much as it used to!