When I went it was in February and the penguin chicks were still downy but getting ready to molt and migrate, they would just careen up to you and it was super adorable. I saw chinstraps and gentoos; some people in the group saw Adelies but they were few and far between. We saw dozens of Humpbacks and several Minkes, and about four kinds of seals. Many other seabirds as well. The ship has several sciency types on board- a geologist, several marine biologists, several ornithologists, so there was lots of opportunity to learn. The wildlife was stunning.
We wore multiple layers, I would have lightweight thermal pants and a shirt and then heavyweight thermals on top of them. Over top of that we would wear waterproof pants and the huge jacket they gave us. Also double layered gloves, a hat, and the boots we were issued. The clothing was pricey but I live in Boston, so I’ll use the thermals again. You only need a set or two. When I was kayaking I wore a dry suit over the first two layers.