At first glance, underwater drones all look alike: a compact body, a camera at the front, a tether at the back. The differences are in the details, and they decide whether you end up delighted or annoyed by murky pictures and a tether that is too short. Here are the points that really matter.
- Depth: Most hobby models are rated to 100 metres; the budget Chasing Dory only to 15 metres.
- Tether: Tether length is not diving depth. For regular dives to 30 to 40 metres, a 100-metre tether is right.
- Battery: “Up to 4 hours” applies to calm hovering. Plan on half that.
- Budget: The mid-range at roughly €1,300 to €1,900 suits most hobby pilots.
1. Where do you want to dive?
The most important question first. For the swimming lake, your boat's mooring or shallow bays on holiday, a few metres of depth are often enough. If you want to explore wrecks, steep drop-offs or deep Alpine lakes, you need considerably more reserve. Most hobby models are now rated to 100 metres; the budget entry-level Chasing Dory only to 15 metres.
2. Tether and depth are not the same thing
Tether length is not the same as diving depth. The tether almost never hangs straight down; it runs at an angle, forms curves and gets pulled along by wind and current. So be generous: if you want to go 30 to 40 metres deep regularly, a 100-metre tether is good advice. Many models come in 200-metre versions, and the FIFISH V-EVO even offers 300 metres as an option.
3. Camera and lights
4K is standard on current hobby models, apart from the Dory, which films in Full HD. Look at the frame rate: 60 frames per second (as on the V-EVO) makes movement smoother, and 120 frames in Full HD (as on the Gladius Mini S) allows slow motion. Lighting is at least as important. Underwater, red disappears after just a few metres, and from about 15 metres everything looks blue-green. More lumens help bring colours back, but only at short range. There is more in our practice article Colours underwater: why everything turns blue, and what helps.
4. Movement and control
Classic drones move like a small submarine: forwards, backwards, turning, up and down. Models with “360°” or “6 degrees of freedom”, such as the FIFISH V-EVO or the Chasing M2 S, can also tilt in any direction and hover sideways. That is ideal for inspections, because you can point the camera straight at a spot. Hold functions such as depth lock or position lock are helpful for beginners, so the drone stays steady while you film.
5. Battery and running time
Manufacturers usually quote “up to 4 hours”. That applies to calm hovering; at full speed, QYSEA says the V-EVO's battery is flat after about an hour. So it is better to plan on half. It also matters whether the battery can be swapped: on the Chasing M2 S it can, so with a second battery you can simply carry on diving.
6. Warranty and dealers in the German-speaking region
Read the warranty terms before you buy. With QYSEA, for example, you get 12 months on the camera and electronics, but only 6 months or 200 charge cycles on the battery and motors, and no warranty at all on the tether, propellers and housing. Chasing requires proof of purchase for a warranty claim. So it is best to buy from a dealer in Germany, Austria or Switzerland who will help you if something goes wrong, and keep the invoice somewhere safe.
7. What budget do you need?
| Budget | What you get | Examples |
|---|---|---|
| up to approx. €800 | Entry level: Full HD, short tether, shallow depth | Chasing Dory (15 m); hardly available any more in Germany, Austria and Switzerland |
| approx. €1,300–1,900 | The hobby mid-range: 4K, 100 m depth, 100 m tether, bright lights | Chasing Gladius Mini S, FIFISH V-EVO |
| from approx. €2,300 | For advanced users: more light, swappable battery, lots of accessories | Chasing M2 S, FIFISH V6 Expert |
Our recommendation for most hobby pilots is the mid-range. It gives you enough depth, tether and picture quality that you won't want to upgrade again after a year.
If your budget is under €1,000, read our guide Underwater drones under 1,000 euros: the best models of 2026, where we are honest about what is possible in that price range and what is not.
In video
The two most popular hobby models in the manufacturers' official videos:
Frequently asked questions
How deep should an underwater drone be able to dive?
For the swimming lake, your boat's mooring or shallow bays, a few metres are often enough. If you want to explore wrecks, steep drop-offs or deep Alpine lakes, you need more reserve. Most hobby models are rated to 100 metres, the Chasing Dory only to 15 metres.
How long should the tether be?
Tether length is not the same as diving depth, because the tether runs at an angle, forms curves and gets pulled along by wind and current. If you want to dive 30 to 40 metres deep regularly, a 100-metre tether is good advice. Many models come in 200-metre versions, and the FIFISH V-EVO even offers 300 metres as an option.
How long does the battery really last?
Manufacturers usually quote “up to 4 hours”. That applies to calm hovering. At full speed, QYSEA says the V-EVO's battery is flat after about an hour, so it is better to plan on half. The battery on the Chasing M2 S can be swapped.
How much does a good underwater drone cost?
Up to about €800 you get entry-level Full HD models with shallow depth. The hobby mid-range with 4K, 100 metres of depth and bright lights costs roughly €1,300 to €1,900. From about €2,300, models for advanced users begin, with more light, a swappable battery and lots of accessories.
What should I look out for with the warranty?
With QYSEA you get 12 months on the camera and electronics, but only 6 months or 200 charge cycles on the battery and motors, and no warranty on the tether, propellers and housing. Chasing requires proof of purchase for a warranty claim. It is best to buy from a dealer in Germany, Austria or Switzerland and keep the invoice.
Before you buy, write down three things: where you want to dive, roughly how deep it is there, and what you want to see or film. With those three answers you can place almost any data sheet in seconds, and in the forum under “Kaufberatung” (buying advice, in German) you will get matching tips.
You can find reactions and comments on this article in the Unterwasserpilot forum (in German, English posts welcome).
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