On the Mix Pro data sheet, two figures follow one another without attracting much attention: 30 minutes at low speed, at 1.2 m/s, and 20 minutes at high speed, at over 1.8 m/s. We usually read the first line as the good news and the second as the price to pay.
Put them side by side and do the multiplication.
The same distance, either way
1.2 m/s for 30 minutes is 2,160 metres. 1.8 m/s for 20 minutes: 2,160 metres too — and the sheet says “over 1.8 m/s”, so slightly more.
In other words, on these figures, speed does not cost you distance. It costs you time in the water. On a full battery you cover roughly the same ground — but at high speed you spend a third less time doing it.
That is a very different way of choosing your speed. The question is no longer “how far can I go?” but “how long do I want to stay?”.
Why speed is so expensive
An underwater scooter isn’t pushing against nothing: it is pushing against water, which is eight hundred times denser than air. The faster you go, the more resistance builds up — and it doesn’t build up proportionally, but considerably faster than the speed itself. Doubling your pace demands far more than double the power.
This is why a two- or three-speed scooter is not a gimmick. Low speed is not a “beginner” setting: it is the setting that makes the quoted runtime real.
How to read “up to 60 minutes”
For the Navbow and Navbow+, the data sheet quotes up to 60 minutes of runtime, depending on the speed selected, across three speeds up to 2 m/s. That wording says exactly what it means: the 60 minutes belong to the gentlest setting. In third gear you will not get an hour — and that is not a flaw, it is the counterpart of 7.2 km/h.
The same reading applies everywhere: on the Whiteshark Mix (up to 5.4 km/h, or 1.5 m/s) as on the Vapor and its 10 km/h. A quoted runtime is always the runtime of the most economical speed.
Three things that shorten your runtime without being counted
- Current. Working against a current, even a weak one, is like riding uphill the whole way. An outward leg against the current and a return leg with it do not cancel out: the way out costs more than the way back gives you.
- Cold water. A lithium battery delivers less when it is cold. In April in the Mediterranean, real runtime is not August runtime.
- What you carry. A camera, a case, a thick wetsuit: anything dragging through the water is paid for in minutes.
The rule that saves you the swim home
It fits in one sentence: go out fast if you like, come back slow. And above all, budget half the battery for the way out — not two thirds.
The arithmetic at the top explains why: at 1.8 m/s, ten minutes out puts you more than a kilometre from shore. If the wind has picked up meanwhile, the return leg will not be made at the same pace as the outward one.
On the Navbow and Navbow+, the screen shows remaining charge in real time, and the SublueGo app tracks runtime during the session. It is the instrument you miss most when you don’t have it.
In short
Top speed is not there to be held for an hour. It is there to get through a passage, cross a current, reach a specific spot. The rest of the time, cruising speed covers the same ground — with thirty minutes in the water instead of twenty.
