Seaweed with little green fingers for ID

Seaweed with little green fingers for ID

Observation - Seaweed with little green fingers for ID - UK and Ireland. Description: I don't know this seaweed (a Brown alga I think) found in a Dorset rockpool and can't find a perfect match for it. A little like Codium fragile, but this has a more complex branching pattern. A little like Cystoseira tamariscifolia but no iridescence not

I don't know this seaweed (a Brown alga I think) found in a Dorset rockpool and can't find a perfect match for it. A little like Codium fragile, but this has a more complex branching pattern. A little like Cystoseira tamariscifolia but no iridescence noted. Any suggestions welcomed!