Discussions regarding the Sidney wharf are taking into account the generally accepted fact of worldwide rising sea levels. On Vancouver Island, there are a variety of tectonic plates that are causing our land to rise as well and rise in some places faster than the sea is rising. Therefore, the changing of the sea level relative to the rising land should be considered, not just the rising sea.
The significant parts of this data published by the B.C. government since 1910, as well as its source, can be found at: https://www.env.gov.bc.ca/soe/indicators/climate-change/sea-level.html.
Taking into account both the land and sea-level changes, the average relative sea level has risen along most of the B.C. coast over the past century. Average sea level rose at a rate of 13.3 centimetres per century at Prince Rupert, 6.6 centimetres per century at Victoria, and 3.7 centimetres per century at Vancouver. In contrast, average sea level fell at Tofino at the rate of 12.4 centimetres per century.
At this time, it is also worth noting that Sidney already has a floating wharf with commercial buildings on it, namely the Port Sidney Marina. The access to its office and docks is by means of a ramp. The marina office and boats are protected from rough seas by crushed-rock protection walls. Would the Beacon floating wharf require crushed rock wall protection?
In summary, the small increase of 6.6 cm per 100 years, in my opinion, should not necessitate building a new dock that is any higher than the existing one, nor having a floating dock to accommodate changing sea level, especially one with a 50-year (maintenance) contract, and possibly needing a crushed rock protection barrier.
My preference is to keep and maintain the existing wharf, and with it some of the attraction and history of Sidney. Consideration could be given to “Snapjacket” marine technology which reinforces existing piles, by pouring concrete into a PVC jacket placed around them.