Boreal Hollow is one of the six fishable pools added to Fisch with the Astral Observatory update, and it is the single biggest contributor to that bestiary. It is not marked on the map, it is not reachable by boat alone, and it sits well above the shoreline of Boreal Pines, which is why plenty of players sail out, fish the obvious spots, and leave without ever seeing it.
Quick answer: Sail to Boreal Pines in the Northern Expedition, equip the Winter Cloak, then climb the snowy cliffs and travel northeast toward north (NE – N) on your compass until you reach the cave entrance at GPS 21385, 249, 3816. Entering it awards +625 XP and the “Newly discovered location!” prompt.
What you need before leaving for Boreal Pines
The trip is short, but the cold will kill you long before the climb does. Bring the Winter Cloak suit and keep it equipped from the moment you approach the island. A glider makes the cliff section far quicker, since the route up is vertical and the ledge you are aiming for is high above the water.
You also need a boat that can handle the run north. Boreal Pines is part of the Northern Expedition, so you are crossing open ocean to get there rather than fast travelling from a shop hub.
How to reach Boreal Hollow in Fisch
21385, 249, 3816. You drop into the cave interior, which is lit blue throughout and holds the Boreal Hollow fishing pool.Note: If you overshoot and end up flying west or straight north along the coast, drop back to the crab cage area and start the climb again. The entrance is easy to sail past because it faces inland, not out toward the water.
How to confirm you unlocked the location
The moment you pass through the entrance, the “Newly discovered location!” banner appears alongside a +625 XP reward, and Boreal Hollow is added to your discovered locations. If you get the glowing cave interior but no banner, you have already unlocked it on that account previously — the XP only pays out once.
Every fish you can catch in Boreal Hollow
Boreal Hollow feeds directly into the Astral Observatory bestiary, which is spread across several pools instead of a single island. Most of what spawns here is locked to night, and winter carries the heaviest share of the rare entries, so plan your visits around the in-game clock and season rather than fishing blind.
| Fish (rarity) | Bait | Weather | Season & time |
|---|---|---|---|
| Celestial Crab (Common) | Magnet | Clear, Foggy, Rain | Any season, Day |
| Peacock Squid (Common) | Shrimp | Rain | Spring, Night |
| Nebulous Comb Jelly (Rare) | Shrimp | Foggy | Autumn, Night |
| Starlit Seahorse (Legendary) | Seaweed | Clear | Winter, Night |
| Boreal Man o’ War (Mythical) | Minnow | Rain | Winter, Night |
| Goliath Siphonophore (Exotic) | Squid | Clear | Winter, Night |
The rest of the Astral Observatory bestiary lives in other pools, including the Astral Cavern near the Cryogenic Canal base camp on the Northern Expedition, a Blue Moon cavern under Snowcap Island, an underwater opening at Abyssal Zenith, and a pond crevice in Everturn Forest. Boreal Hollow alone will not complete it.
Triggering the Goliath Siphonophore hunt
The Goliath Siphonophore is the Astral Observatory update’s hunt fish, and it will not appear just because you are standing in the right cave. The hunt is triggered by building disturbance in the main pool outside, behind the reinforced crab cage doors. Fish the main pool until the hunt goes active, then move into Boreal Hollow and cast there.
Order matters. Sitting in the hidden pool and waiting will not spawn it, and staying in the main pool after the hunt starts means you are fishing in the wrong place for the actual catch.
The reel itself behaves differently from a standard exotic. The Goliath Siphonophore can temporarily freeze your progress bar mid-fight and cut your resilience while you are holding the fish in the catch zone. Neither effect is a bug. When the bar stalls, hold your position instead of overcorrecting, and push progress during the windows when it starts moving again.
Boreal Hollow rewards a bit of preparation more than most Fisch locations. Get the Winter Cloak on before the climb, use the crab cages as your anchor point, and time your return trips for winter nights when the Starlit Seahorse, Boreal Man o’ War, and Goliath Siphonophore are all available in the same window.
