 Japanese title card · “The Water Planet Hydo” | |
| Series | Sonic X (ソニックX), TMS Entertainment |
| Season | Season 3 (2005–2006) |
| Episode | Season 3, episode 3 · no. 55 of 78 |
| English title | “H2 Whoa” (4Kids) |
| Japanese title | 水の惑星ハイドー (Mizu no Wakusei Haidō, “The Water Planet Hydo”) |
| Japan | Not shown on Japanese TV until 27 March 2020 (Kids Station) |
| First aired (US) | 24 September 2005 · 4Kids TV (Fox) |
| Directed by | Masami Furukawa |
| Written by | Hiro Masaki |
| Storyboard | Seiji Okuda |
| Previous episode | Cosmic Crisis (S03E02) |
| Next episode | An Enemy in Need (S03E04) |
Metarex SagaWater planet
H2 Whoa is episode 3 of Season 3 of Sonic X and the 55th of the anime’s 78 episodes. In Japan it is called “The Water Planet Hydo” (水の惑星ハイドー). It premiered in English: 4Kids aired it on 4Kids TV (Fox) on 24 September 2005, after a French TV debut on 13 March 2005, while Japanese TV only showed it on 27 March 2020. It was directed by Masami Furukawa and written by Hiro Masaki.
Synopsis
On Earth, Chris’ family and friends find the note he left beside his teleport device and realise where he has gone. Out in space, the Blue Typhoon reaches its first stop: Hydo, a world that has turned into one great ocean since the Metarex took its Planet Egg.
Knuckles senses a Chaos Emerald, and Sonic and Chris head down in the landing craft. Sonic, who hates water at the best of times, is captured by fish-like Metarex, and Chris has to retreat to the ship without him.
Chris doubts himself and wonders whether he should have come at all, until a memory of designing shoes for Sonic with Helen gives him an idea. Amy, meanwhile, bursts into the room where Sonic is held – and falls straight into a shark tank.
Key Moments
- The Blue Typhoon’s first planet: the water world Hydo.
- Sonic is captured by the Metarex.
- Chris finds his courage.
Japan vs 4Kids
- The planet Hydo of the Japanese version is called Secco in the 4Kids dub.
More on the English version’s changes in the Season 3 dub differences box.
Trivia
- The English title puns on H2O, the chemical formula for water.
- On home video: the The Complete 5th Season DVD set (2006); and Discotek’s Sonic X Collection 2 (2016) and complete-series Blu-rays.
Watch the Episode
The full 4Kids English episode, uploaded by TMS Entertainment’s official “Anime! on TMS” YouTube channel (checked 6 November 2026).
Part of our Sonic X Season 3 guide. See the Sonic X series page for the cast, theme songs and home video.
Sources: titles, credits and air dates from Wikipedia’s list of Sonic X episodes and Sonic Wiki Zone, cross-checked with each other and with Luke’s original Sonic Scene episode table; synopsis written for Sonic Scene from the episode, Wikipedia’s summary and Sonic Wiki Zone’s plot notes; title card and screenshots via Sonic Wiki Zone, copied to our media library.