Currently the spring tides are quite extraordinary. We are seeing huge tidal ranges, and some mouthwateringly low tides. To put it into context, I have devised this little number...
Bad low tide - Anything over 1.5m
Typical low tide - 1.1m - 1.5m
Spring low tides (the good 'uns) - less than 1m, usually around 0.8m
Last nights low tide - 0.42m, and tonights 0.41m 
Quite incredible really!
Obviously that gives us our best chance of finding something that would normally be happily swimming around in the sea, as the large tidal range and very low tides double up to create an even harsher environment, with sublittoral and offshore fish more likely to be swept into low shore rockpools. Last night we visited Scalby, and rather than stick up a load of photos of organisms you've all seen before, I thought I'd explain a bit more about the type of shore that Scalby has - hopefully I can compare it to Holbeck's rocky shore which we are visiting tonight.
At Scalby, the structure of the shore is quite different to Holbeck. For one, it is much bigger, and the rocks are larger, making rockpools more sheltered. This gives a different spread of organisms (eg, sea slugs only present at Scalby, as they prefer sheltered shores, as do echinoderms such as Starfish and Sea Urchins.
Here is your typical rockpool...
You have to put up with copious amounts of kelpweed that is slippy, gets tangled around your legs, and obscures your view 
What is more interesting however, in terms of the structure of the shore at Scalby, is the view around you when in a rockpool...
At Holbeck you would be able to see much more of the sky, and less of the rocks, but at Scalby, rocks are larger, and jut out everywhere. Although it makes navigating more difficult, it at least gives us a more sheltered shore as mentioned earlier.
When you get to the very edge of the low shore, you stare into the sublittoral....
At very low tides, a good portion of this is exposed enough to lift rocks over, like last night. Usually though, this zone remains submerged, no doubt concealing all sorts of mystical marine life 
The above scene will greet you at Holbeck as well, except the water there is usually clearer, as freshwater runoff from Scalby Beck and the nearby cliffs (depending on your shore location) makes the water at Scalby more silty.
Despite the occasional silty rockpools hampering visibility, there are some lovely sheltered pools which are largely unaffected by runoff, and are therefore clearer...
The rocks themselves can harbour some interesting organisms like this blue star ascidian (Botryllus schlosseri)
Thanks no doubt to the very low tide, we also found our first painted top shell, which is only found at very low water and in deep water...
Edible sea urchins were also found. This time we saw at least 40, although even that estimate is conservative. We didn't bother collecting them up this time. Instead I thought it would be a good idea to photograph them exactly where we found them - you will notice that some are not even underwater!
So they're not too difficult to spot, as you can see 
The last thing I wanted to mention is the freshwater river. We rockpool well away from the mouth of the river, but the brackish environment in the pools in front of the river mouth are worht exploring in summer during daytime low tides.
Here you can see the river flowing into the sea...
Finally, here is a very odd looking long exposure of the above picture. 13 second exposure, and a cool result IMHO
Thanks for viewing! 
More to come tomorrow after tonights Holbeck visit 
Steve