From the top of my head: 1 Canada Place downtown for cruisers; ferry to North Vancouver; N. Vancouver shore with its view of container terminal and Vancouver Harbour, Stanley Park northern sea promenade (under Lion's Gate Bridge) for vessels entering the harbour, also western part of the park coast for vessels at anchor.
A bit outside of Vancouver: Steveston Harbour, with the view of the mouth of Fraser River.
Also: a ferry ride to Vancouver Island, either from Horseshoe Bay, or from Tsawwassen ferry terminal, with the view of Delta Port.
Rgds
Vlad