We've seen Teslas float before, but not like this.
We've even witnessed a real Tesla Model S floating before, so the words of Musk are indeed true. In fact, electric cars are better equipped to deal with large amounts of floodwater than gas or diesel vehicles. This is due to the fact that in electric cars, the vital components are fully sealed, whereas gas/diesel vehicles require intake air to function and this opening is where water can easily enter and quickly hydrolock an engine.
Back to the Cyber boat though. It's the creation of hypercarslands on Instagram and it's quite a slick bit of CGI animation. The video shows the Cyber boat moving along the water while a guy fishes from the comfort of the Cybertruck bed.
As hypercarslands states:
The Tesla Boat Mode
The ability to float could be a rather useable feature for the Cybertruck in extreme off-road situations. It doesn't make much sense for other Teslas to have this unique ability, but floating with some slight bit of propulsion could set the Cybertruck apart from gas/diesel pickup trucks.
More important than its ability to float though is its fording depth and we expect the Tesla Cybertruck, with its active adaptive air suspension, to be among the best in class for fording for pickup trucks.