Your compositions are good, however the photos are not completely in focus, and too blue. You need to get the white balance right so that it looks natural. For commercial stock you need to remove all trademarks and logos. No watermark is allowed. That include your signature. Photos are also grainy, and underexposed. You need to use a photo editor to correct the issues of your photos. When correcting, you will need to zoom to between 100 and 200%. However since they are also not completely in focus, I do not think these will be accepted. The edges of your subjects need to be sharp so that they can be removed from their background if the customer need to do so.
Please read the guidelines of all the subjects in the following links.
Hello @jacquelingphoto2017, thanks for the link of the guide and for the advices. The out of focus area actually is a blur that I added intentionally so the boat appears more as the subject of the image. The sky was totally cloudy that day so I photoshoped it to be clear blue. That's why the highlights look out of range. Alltough the sharpness I tried to add it on lightroom but I didn't quit naild it. I agree with you for the high blue color in the photo.
I will remove the signature and the blur and re-submit. Thank you again and best regards.