I find the patterns that form on the sides of icebergs to be fascinating subjects. I made hundreds of different images with just one iceberg, playing around with framing to get interesting patterns. Though this was made with a 400mm prime, the flexibility of a zoom lens is very useful for this kind of work.
Patterns in Ice
Patterns in Ice - 5D3, 400, f/5, 1/1250s, ISO 100