Martin, this post struck a chord with me and it's how I felt about my early day shots at dusk. I've realised that you can't do the impossible with particular lenses. If you had an f2.8 then you would have improved on these photos but I think your lens is f4-5.6 and at the 300mm end, which you were using ,f5.6 isn't up to the job at the speed you need even wanging up the ISO which just gives you unacceptable levels of noise. The first photo was wide, you say (I took it into photoshop but there's no exif data available)) and no doubt you were able to take the shot at the f4 end,combined with a high ISO and a slowish speed you got a decent shot but as for the 300mm end you can't change the laws of light physics Lol.
Those ships with their lights on gave me a good idea about the level of light you were working with and also the one with the houses in and to make matters even more difficult you were fighting with gale force winds if not storm force. It was your determination that took you to that location even though you knew in your heart that it was going to be an uphill struggle. As you said you needed a fast shutter speed to 1.. get the scene reasonably sharp and 2. to freeze the 'action' and you ain't gonna be able to do it so why beat yourself up trying to do the impossible ? I've gone past that stage now and recognise the impossible when I see it. Do you know that you can get spikes for your tripod ? They are invaluable when you can press them into to soft ground. I was battling against a gale with my sunrise photos but the spikes in the ground gave me a great deal more stability.
http://www.morrisphoto.co.uk/ProductDetails~productID~5521~categoryid~149.htmlHope this helps to put this batch behind you - you'll soon have a daytime storm - remember those photos when I said you'd taken a risk getting onto the rocks down at the wave level especially as you were on your own - they were excellent ,so chin up old chap.