Silky Smooth Water Attempt

Hi everyone,
I haven't been doing much photography at all thanks to uni and work but the other day I had the urge to try and get some long exposures of water. I don't own any ND filters so I had to wait till sunset to have it dark enough to be able to have long exposures so bear with me! It was shot with a D3100 using the kit lens and has been processed in LR4.
There is slight fringing around the land in the top right of the photo. Is that due to too much post processing or just because the contrast between land and sky is too much?
Let me know what you think and where I can improve!

ISO100
26mm
f/4.2
15 sec

The fringing is definitely from post - likely cooking the clarity, contrast or sharpening. For silky water you could definitely have used some more time as the patterns are still clearly visible, but I understand the limitations without an ND. Grab a 9-10 stop and don't look back. But given that you were only shooting at f/4.2, you could have closed up to f/11 or so and gone for over 30 seconds without an ND.

As for you pic, in Photoshop and Elements there are things you can do with layers and masks that will allow you to add blur to the water (quick & dirty example below - it needs cleanup around the rocks)...



...but it's not as natural looking as what you'd get with more time. In LR you can use the brush tool and brush some negative clarity on the water to similar effect. After that, use the selective saturation and luminance sliders in the HSL section of the develop module to make the colors on the cliff pop a bit, and maybe warm it up a bit...



Even without messing with the water textures, the color and contrast enhancements will make the photo pop more.

All that said, it's a nice photo, and a very good first attempt. Keep at it!!

All I can say is you live on the absolute BEST part of the coast to get great sunrise/sunset photos with the sea running over rock platforms. Do yourself a favour and get an ND filter. You can buy a cheap variable ND filter for about $40 if you don't want to spend heaps and get reasonable shots with it (not too much colour cast).

Thanks guys!
Jake, you're right, I should've exposed for longer now that I'm seeing it but at the time I thought 15 seconds was going to be plenty! I'm definitely going to head back for some more shots soon though. Would you say 30 seconds is about right because the D3100's LCD screen is shocking so it's almost like guess work. I wasn't sure if I should bring out the details in the cliff because I though it might look a bit "fake" considering the light is coming from the other side, so really, they should be in dark shadow?
Vixen, I agree that this part of the coast is most definitely amazing. It's got some serious potential for nice shots, I just have to go out and get them!
Thanks for the feedback.

With water it's often a matter of shooting, looking, adjusting and shooting again. Some water will be too washed even after 6-10 seconds, others needs almost a minute. I've got a remote that will let me trigger in bulb mode so I can get things like 22 seconds, which the camera won't give me. I would have thought 15 was enough for tidal stuff, but I guess not from that perspective. Like everything, there's no magic formula, just try and try again.