Actually artificial reefs examples can be found outside of the water. We have one on the grounds of our local high school. Interesting to see what is below our waters.
Women in History is a great idea. I think you need to make sure you include all forms of memorials, signs, plaques, statues. There are many out there that get overlooked.
The motorcycle colors I also am not familiar with. Possibly if you can explain more and give detail we can look at it more. Good luck with all your attempts. The first time can be hair raising but don't give up.