Wedding dresses for beach wedding should be more casual and simpler because the weather factor can influence your comfort and ease. If you have a gown or a dress that has too much ornamentation and would like to tone it down to suit the casual beach event, then may be you can have it altered to simplified the heavy feel of it. May be if it has a long train, it can be removed, or try making it a halter top style.
Also, try using a small tulle veil or none at all, that way the overall look and feel it’s not as heavy. May be a flower or small hair ornament will lessen the heaviness of the dr