The trailer is quite narrow and fits between the Pontoons. The Trailer actually lifts the deck of the Boat and does not support the Pontoons and the wheel base is quite small. This style of pontoon boat trailer can be retrieved and launched in the shallowest of water, since the Pontoons are very low to the ground.
Tanking is, as its name suggest a method of sealing a wall to prevent water ingress (think 'water tank). often mis-specified as a cure for damp problems it is basically a waterproof cementious slurry (wet mix) that is applied to a surface to prevent water penetrating the internal surface of a building..
Wall-Jumping is a technique used in Scratch to make sprites bounce off walls. This allows a character in a project, for instance, to scale up massive heights of walls rather than jumping on individualized sections like stairs. It is commonly used in platformers. This is just one of the ways for wall jumping to work.