With the advice further up-thread I have bought Hoya 3 & 10 stop ND filters.Yesterday, despite the drizzle, wind still blowing a gale & grey skies I went to Lepe beach on Southampton Water where there are the remains of the D Day embarkation structures. The sea was rough which made the water white out in some images and there was no interest in the sky. The tide ideally could have been lower.
I was also hurrying to beat the oncoming rain, so probably didn't set up as well as I should have - I forgot to switch off image stabilisation and there is also an easier way to set and lock manual focus which I will use next time.
The little Fuji can't shoot longer than 30 seconds by default & can't go beyond f11. As a consequence this still only gave about 15 seconds with the 10 stop, so I stacked both filters for a few shots as an alternative.
I think this type of photography is at the limit of the X10 compared for instance to the X100 or a DSLR. I'm also not sure if the loss of definition was my inability to set accurate focus (probable), the high wind or the unstable, sloping gravel beach to set the tripod up on.
However, it wasn't a total failure so I will put up a couple or so examples in the photo of the week thread. It gives me some hope for a better outcome with better conditions. Thanks for the help