This hoverboard doesn't have any unlockable upgrades.
Big Blue is the 43rd limited hoverboard in Subway Surfers. It is a limited hoverboard released in . Like any other hoverboard, it protects you from crashing for 30 seconds. When crashed, the hoverboard will explode and need to recharge for a few seconds before using again. It costs 50,000, just like most of the others limited hoverboards.
It was used as a board display on the map along with Great White, but it did not return in . Great White still had the same cost, but was not used in any Bundle.