Any underwater drones small enough to fit in aquarium?

This Mini Scuba Tank Fits In Your Pocket! V2, Twice The Air + Lights / Lasers (007 / Star Wars)

150M Tether Titan Professional Underwater Drone ROV AUV Robot with 4K UHD Action Camera Remote Control Real-time Steaming Undersea Detection for Viewing, Recording, Fishing, Salvage Work (150M Titan) : Electronics

Underwater Smart Fishing Drone

Water, Free Full-Text

Index of underwater diving - Wikipedia

Aquascaping: 'landscape gardening, but underwater

This Powerful Mini Doc Packs A Punch Through Short-Form Storytelling, Sony

150M Tether Titan Professional Underwater Drone ROV AUV Robot with 4K UHD Action Camera Remote Control Real-time Steaming Undersea Detection for Viewing, Recording, Fishing, Salvage Work (150M Titan) : Electronics

I 3D printed a fully functional underwater drone. Here's the complete build video (update) : r/3Dprinting

Found!!: Lost my Mini 3 Pro in a lake, i have care coverage just wondering if it's cheaper to recover it (hire a scuba diver to find it) or not? : r/dji

U.S. revives Cold War submarine spy program to counter China