Effectively a pimped version of its marginally lighter forebear, the F5, this sleek sea scooter is faster even than Cayago’s elder statesman, the flagship F7. At 35kg, the F5 S boasts a propulsive force of 680 newtons, ensuring it will hit 20km/h on the surface and up to 15km/h beneath it. The six-speed, electric E-Jet Power engine runs for 60 minutes, sucking in water via a rotating impeller and then forcing it out of the stern under high pressure. A colour display lists the remaining operating time, water temperature and depth – oh yes, it can also dive to 40 meters. Cayago says the hydrodynamic F5 S is so maneuverable you can even ride it in larger pool complexes. Whether this is a wise course of action, Brogue will leave for you to decide. €10,780 seabob.com