Heartopia: the Underwater Mount Guide — Unlock Your Underwater Home Before August 22

Whale Season closes its doors on August 22 at 5:59 a.m. server time, or 12:59 p.m. Paris time. Of everything the July 11 update poured into Heartopia, only one thing is designed to stick around for you: the Undersea Mount, the private plot built at the bottom of the Whale Canyon. The official announcement is clear about its status — these plateaus spotted by the marine archaeology team fall under the Island Development Association, and they're accessed via the Undersea Mount Management Console.

The catch lies elsewhere. This console can't be bought and won't show up in the mail: it's earned at the end of an entirely seasonal progression chain. A Builder who puts this off until September will indeed keep their plot, but they'll have let the dolphins slip away, along with part of the Whale Canyon Exploration Handbook rewards and the co-op cleanup event.

Twelve days remain. Here's the game plan, with the exact labels from the French client.

What the console actually unlocks

The Undersea Mount is a buildable underwater plot, independent from your home. The Whale Season announcement specifies what it supports: blueprints, multiplayer building, and tours. You swim there, you build there, you take photos from every angle; unlike a land plot, verticality is part of the playing field here.

Two mechanics are unique to it. The first is the ornamental fish schools: you release fish taken from your bag or from storage, and they stay in place as living decor. The second is the ecological level: by feeding the zone with the materials the console asks for, you raise it and unlock more impressive schools. XD slips in an atmospheric line about "very particular" animal visitors that the zone would eventually attract — we'll come back to that below, it's not just flavor text.

One detail that matters for anyone following guides written in July: the August 5 hotfix fixed a mismatch between the levels shown in the canyon's progression description and the actual upgrade levels of the Undersea Mount's fish schools. Any screenshot taken before that date may therefore show false milestones. Trust the in-game console, not a table copied three weeks ago.

The unlock chain, step by step

• Prerequisites: be a Builder level 7 and have completed the main tutorial quest "The Answer Is Here". Without these two conditions, the Whale Season itself remains locked.
• Entering the area: the portal is located near the Whale Mountain. Once inside, swimming is free in every direction.
• Open the Whale Canyon Exploration Handbook: this is what drives zone progression and hands out the themed outfit "Sea-Valley Vacation" as well as the furniture set "Inflatable Whale House", which became colorable with the July 22 maintenance.
• Exploration level 2: this is the tier that grants the basic sea cleaner and unlocks the Marine Cleaning passion. Community reports (GameRant, heartopia.life) add that you need to spend an exploration certificate to clear it; XD has not published this detail in its French announcements.
• Canyon investigation missions: this is the only condition officially cited by XD to obtain the Undersea Mountain Management Console. On the player side, the threshold consistently reported is exploration level 5.

Once you've obtained the console, it's used at the entrance of your home, near the mailbox. It's the same item used to manage permissions, start a co-build, and visit a friend's undersea mountain — provided their permissions allow it.

Leveling up exploration without spending every evening on it

The exploration meter fills up in four ways, and only one of them is really time-consuming.

• Cleaning. Each pollutant dealt with grants passion experience and exploration points. It's the main source, and it never runs out.
• Gathering. The zone's three new ingredients — sea grapes, sea asparagus, and wakame — also feed progression. Pick them up along the way, never as a detour.
• Chaining local quests and daily requests in the canyon, which remain the best time-to-points ratio.
• Popping the daily bubbles, added to the zone by the July 22 maintenance. Free, quick, worth doing every time you log in.

The tiers, meanwhile, require exploration certificates in addition to points. Community reports describe ten levels in total, with tool durability increases at levels 4, 6, 8, and 10. In practical terms: if your cleaner wears out within a few minutes, it's not a balance flaw, it's a tier you haven't cleared yet.

The four types of pollutants, and the Corrupted effect

XD sticks to a vague formula: some waste requires several passes, others good timing. The details come from player reports, and they completely change a session's efficiency.

The Corrupted effect is the system's only real obstacle: during the operation, you can get contaminated, and your stamina then drops noticeably faster. Three ways out exist, two of which are underused — the cleansing anemones scattered around the canyon, help from another Builder, or a bath at home. In a short session, the nearest anemone saves you far more time than a round trip home.

The shells collected once the pollution has been dealt with feed into a collection: the illustration points notably unlock the pearl-shell curtain and the coral-shell display case. Since August 1st at 6 a.m. server time, the Sea Cleanup event adds giant pieces of trash on top, to be dealt with alongside other players, with exclusive rewards. It's the best hourly yield in the area, provided you show up when other players are online.

Dolphins: the only part that really expires

The game's official account is explicit: the dolphins are a seasonal species and will leave Whale Island at the end of the Trend Season. During the season, you feed them and interact with them in Whale Canyon to raise the bond with the group, and they come visit the underwater mount, bringing gifts. This is the famous "very special visitor" from the announcement.

The decisive point is tier 4 of this bond: it unlocks the feature that XD refers to as "Life Fragment" on its English-language account. No French Steam announcement names it as of now, so we're keeping the original wording rather than inventing a translation. Its appeal comes down to one sentence: it survives the dolphins' departure: after the season, you'll still be able to receive some. Reaching tier 4 before August 22nd is the only truly unrecoverable objective in this entire guide.

Note that this system has been tweaked twice in a month: the July 22nd maintenance fixed an issue with the dolphins' gifts, then the August 5th hotfix optimized how it works. If you gave up in July because the gifts weren't dropping, the current behavior bears little resemblance to that.

Twelve days, in order

If you're starting from scratch on August 10th, here's the breakdown that wastes the least time.

• Days 1 and 2: reach exploration level 2, get the sea cleaner, get into the habit of dealing with ordinary trash.
• Days 3 to 5: chain investigation missions, daily requests, and bubbles until you reach the console. This is the unavoidable block, the one you can't parallelize.
• Days 6 to 9: feed the dolphins every day in the canyon — bond progress is daily and can't be caught up in one evening — while simultaneously raising the underwater mount's ecological level with whatever the console asks for.
• Days 10 to 12: decoration, fish schools, photos, invitations. None of this has a deadline, but it's more enjoyable to do while the dolphins are still around.

What you keep after August 22nd

What remains are the zone, the Marine Cleaning passion — announced as permanent —, the plot and everything you've built on it. What leaves are the dolphins, the season shop and the limited collections. The consequence is counter-intuitive: from now until the 22nd, decoration must take a back seat to cleaning and the dolphins, even though that's obviously the most tempting part. You'll have all of September to furnish your seabed; you won't have a single extra hour for bonding with the dolphins.

One last point for those interested in the topic beyond the game: the season is tied to an awareness campaign around the Indo-Pacific humpback dolphin, with a prize draw reserved for players who reach certain passion milestones. The details haven't been shared on XD's French-speaking channels, but that's one more reason not to leave Marine Cleaning sitting at level 2.