Hey,
Great pics! I like the sharpness of the P'snap ones, and the composition of the others. I've taken a lot of pics at Capernwray, and I think it is fair to suggest that the viz is normally better as the water cools. For the real sharp shots of the wrecks, shoot them in March!
The bright sun we are having at the momment does present challenges, particuarly for point and shoots. Try and use parts of the wreck to actually hide the brightest areas-creating a silhouette.
Like this!

Most cameras struggle to cope with the extreme range of tone from bright sunlight to underwater shadow.
As Tim has suggested, if you are after "atmospheric" shots, you might try and underexpose, but personally I like the fact that Capernwray is bright and light (particuarly when the sun shines)and try to show this in my pictures.
As always in underwater photography, the closer you can get to the subject, the better the image will be!
Adam