Prussian Ice

A new kind of ice called Prussian Ice that is more slippery than Blue Ice. Crafted using 9 Blue Ice, it has a darker texture than Blue Ice. Boats on Prussian Ice travel at 160 m/s, a significant improvement over Blue Ice's 70 m/s and items in water currents on Prussian Ice travel extremely fast. Also, unlike all other kinds of ice, mobs and minecarts in water currents on Prussian Ice travel faster than in normal water currents.

If spiders or cave spiders are in a water current on Prussian Ice, it should be fast enough to prevent them climbing on walls to save themselves. Also, the sides of Prussian Ice should be slippery enough to prevent spiders and cave spiders from climbing onto it, causing them to slip down and take fall damage unless they manage to cling onto another block.