Alphabet Challenge - D is for Diver

It’s my fault - I actually set the challenges! I thought I would use  a theme of ‘occupations’ - anything loosely connected - either the person (or animal, bird, insect), the thing it produces, where it does it etc, Architect, Baker and Candlemaker were quite easy  - but Diver???? The only thingsI could think of produced by diving were pearls, coral, shells and buried treasure from wrecks etc.  (none of which I have handy!) I hoped to get some photos of diving birds - either on the river or in the air - but the weather was awful this week, rain, storms, winds… so I didn’t venture out far with the camera. 
Then, today, I had a thought  - back in the early 1960s I visited the Greek Islands, where local lads free-dived to collect natural sponges from the ocean and sold them to the tourists. (I don’t suppose they still do it -‘elf and safety, you know!) Miraculously I could still find the one I bought  - never used it.
So here it is - the fibrous skeleton of a plant or primitive animal species culled from the sea bed 60 odd years ago!
E is for Engineer - should be easier to find something for that ;-)