I'd still like to explore the ground on the far left of the top picture where it shows a shallow area of blue on top of the yellow/orange.
This is either shale on top of sand, or sand on top of rock, depending on how you interpret the colours.
I still have a hard time believeing that the pinicle is sand (yellow/orange), but maybe the tide can scour these types of features in harder sand, or could it be a soft rock??
Remember, the formula of 1 minute equals 400ft can only be applied in the E-W direction. For N-S it is a non-linear figure depending on your latitude. Not sure what the average figure for our latitude is. Does anyone have an idea?
By the way, great topic Duncan
BF