Browsing through my local chandlery, I came across this useful slide chart. It is a two sided ‘sleeve’ with a sliding inner sheet constructed of tough plastic.
One side shows the Isle of Wight along with South Coast, the other is a close up of the main shipping channel and entrance to Southampton water. However, there is more to this than a simple 2 sided chart!
Both sides have small circular holes cut out a key points in the chart. The inner sheet contains symbols depicting the direction & rate of tidal flow.
You slide the sheet until the correct time before/after high water is showing at the bottom of the chart and each of the holes now displays the rate/direction of tidal flow at that given point in time.
The actual chart is very basic – lacking the detail you would find on a normal sailing chart. Land, land exposed at low tide and the sea along with gridlines for longitude and latitude and some simple contour lines. It also shows the main buoys found in the Solent area.
The whole chart slide is made of tough plastic, therefore completely waterproof and would accept chinograph pencil marks or a permanent pen (which could be cleaned off with meths or similar).
The rigidity of the plastic means this is not particularly flexible so it may bend to more rounded decks but not the more v shaped decks.
As a tool for planning a paddle in the Solent or Isle of Wight area I think its a good purchase at £15 due to a) the information it provides and b) the tough construction. Not sure if they are available for other areas but worth looking out for!