How to get the Heat Upgrade for the Submarine in Fisch

The Submarines in Fisch have upgrades, and you’ll need to get your hands on some precious fish and materials to take your underwater vessel to the next level.

Roblox Fisch’s latest update brings the highly anticipated Mariana’s Veil to the game, where you need to use your Submarine to go down the Roslit waters to find different levels. Some levels have requirements you must complete to gain access to the next zone and obtain the Dr. Glimmerfin suit, which is resistant to different temperatures. If you’re looking to acquire the first Heat Submarine upgrade, we’ve got you covered. 

Here’s everything you need to know about the Heat upgrade for the Submarine in Fisch.

How to get the Submarine Heat Upgrade in Fisch

To get the Submarine Heat Upgrade in Fisch, you must first go to the Volcanic Vents. Once you’re there, you’ll need to collect a list of materials in exchange for the upgrade.

How to reach Volcanic Vents in Fisch?

Navigate your way from the Roslit Ashfall area and go down the tunnel by descending into the hole. Avoid the structures and vines to slowly move and find the Volcanic Vents area using the Submarine. Keep descending until you find the black ground and volcanic walls. Then follow the route to reach the new region. After you surface, leave the driver’s seat and get out of the Submarine using the sail to reach the area. 

You should find an Innkeeper here near the tent. Give him C$35 to stay and spawn there until you change your location. The Volcanic Vents area is full of magma, so there’s a risk of getting burned while making your way to the fishing area and purchasing the new fishing rod. Even if you die by falling in the magma, you don’t need to come back down from Roslit because you’ll spawn directly in Volcanic Vents.

All Heat Upgrade Submarine resources in Fisch, listed

Near the Innkeeper, there’s an Alter which requires you to find four resources. In exchange, you’ll receive the Heat upgrade for your Submarine and the Dr. Glimmerfin suit to protect you against the heat environment of the Volcanic Vents.

The four required resources are Lava Crystal, Inferno Hide, Blisterback Blenny, and Infernal Iguanafish. Collecting the Lava Crystal is the easiest as you just need to find the lava-colored crystals next to the Altar and use your Drill on them. You’ll eventually obtain the Lava Crystal after a few attempts.

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The next step is to fish for the Infernal Iguanafish, Inferno Hide, and Blisterback Blenny. To fish in Magma, you need a special Exalted enchant on your fishing rod or have one of the two special fishing rods with that capability.

Go straight from the Altar and turn left to find a place that resembles a fishing spot. Pull out your Advanced or normal glider and fly over the area to head in the right direction. Keep following the path until you finally find the spot where you can fish. You can use any rod here to fill up your bestiary.

The Infernal Iguanafish likes windy nights and prefers Insect bait. It’s fairly easy to get using the low-tier fishing rods. The Blisterback Blenny likes clear summer days, and you’ll hook it easily by using the Fish Head bait. It is a mythical fish, so it might take a while before you get it in your inventory. Lastly, Inferno Hide is the hardest to get and it depends on your luck, so just keep fishing until you get it to complete the requirements.

Once you get all the materials, head back to the Altar near the Innkeeper and submit it all to obtain the Heat upgrade for your Submarine. This will make your Submarine completely orange, and now you can drive it deeper and reach the next region—Challenger’s Deep.