Gary, you will need to re-size the image. This is a pretty common issue in many websites that allow media content insertion into posts.
Not knowing what tools you may have, try opening the image in Paint, Photoshop or any other image editor you have and resize for web display...once you've done that you should be able to upload it with your post. Good luck.
I'm terrible at this . I just know I have to resize every photo I put up here. I resize to 1000 pix by 800 pix and that works fine. I'm not very good at computer stuff. I don't think you have to resize on the wooden boat website. Sorry ,not to bring up website issues. I think this site works fine but then I'm not to computer savvy.