Much better photo.
I believe it's
Predaea
P. tumescens most likely, and a vividly-colored specimen too.
Below is a good-sized specimen --yours would be but a fraction of it.
(apologies to Chris Lobban, from whose UOG website the photo comes)
I'd try to anchor it too, but lightly. Any contact point on the alga will do. Worth a try for such a good-looking alga.
Can I have your permission to use your photos for an online article?
If you're willing, I'd appreciate a PM giving me the name you want your photo credited to (in the prior photos I posted), the photographer's name is indicated lower right.

hth