As part of my involvement with the 'Debris of the Month' and Marine Debris in general I can show you just a fragment of what i do with the attached Gallery.
Being a very active PADI Course Director, I conduct a lot of Instructor level specialties. Every time I teach the Search & Recovery specialty on Koh Samui, I go to Chaweng Beach and collect debris as part of the course.
Over the years, since I started as a PADI Course Director back in 2003, my students and myself have collected various kilos of debris, ranging from plenty of lost masks to big sun deck chairs and everything i-between. Especially popular seem to be empty bottles and plenty of clothing and sun glasses.
One of the stranger items we found was an (empty) wallet and a Pentax camera that still functioned all during one dive.
I can only urge all other Instructors and Course Directors to combine the Search & Recovery specialty with clean up activities. You get to practice the patterns and the use of lift bags to get the debris out of the water and it gives a very satisfactory feeling after the dive!