Building a base in the alien oceans of Subnautica 2 is a deeply satisfying process, but it can come to a frustrating halt when your brand-new Tadpole Dock refuses to accept your vehicle. The dreaded “insufficient space to dock” message is a common early-game hurdle that can leave players circling their base in confusion. The good news is that the fix is straightforward, cheap, and only requires a few moments with your Habitat Builder. If you have been locked out of your dock, here is exactly what is happening and how to resolve it for good.
Why Your Moonpool Is Rejecting the Tadpole
The root cause of the problem is deceptively simple: your Moonpool is not physically large enough to accommodate the Tadpole. When you first construct a Moonpool room, it comes with a standard, compact footprint that is perfectly sized for the smaller, earlier submersibles. The Tadpole, however, is a more advanced and slightly larger craft, especially once you begin outfitting it with different chassis modules. The game’s docking system is precise; it measures the interior volume of the Moonpool against the dimensions of your returning vehicle. If the Tadpole is even slightly too wide or too long, the mechanism will refuse to engage and you will see the error message. The only cure is to expand the Moonpool’s internal dimensions.
How to Enlarge Your Moonpool Room
Fixing the issue requires you to modify the structure of your base. You will need to have your Habitat Builder equipped and a small stock of Titanium ready. The process involves two distinct steps: expanding the room itself and then expanding the Moonpool fixture within that room.
Step 1: Expand the Room Walls
Begin by standing inside the room that contains your Moonpool. Access your Habitat Builder menu and navigate to the Rooms category. Select the Room piece and aim your cursor at one of the existing walls. A hologram will appear, showing you where an addition can be placed. Confirm the build to extend the wall outward. This will consume a small amount of Titanium. You should repeat this step at least twice for each wall to create enough floor space. The goal is to create a spacious interior that gives the Moonpool fixture room to grow.
Step 2: Widen the Moonpool Itself
Once you have enlarged the surrounding room, you must directly modify the Moonpool. With the Habitat Builder still active, switch to the Moonpool category (the same menu you used to build it initially). Aim your cursor at the side or edge of the existing Moonpool structure. This is often the trickiest part of the process, as the green build hologram can be finicky to trigger. You may need to move your aim point slowly around the edges of the pool until the system recognizes your intent. When the hologram appears, confirm the build to add another section to the Moonpool. For a standard Tadpole, you will need to add at least two size upgrades.
Special Considerations for Haul Chassis
If you have upgraded your Tadpole with the Haul Chassis, you will face a slightly greater challenge. The Haul Chassis is significantly longer and wider than the standard Scout Ray Chassis. This means your Moonpool will need to be both wider and considerably longer to accommodate it. Do not become discouraged if your first few expansion attempts do not work. You may need to add four or more segments to the Moonpool in total, and you might need to expand the surrounding room again to prevent structural clipping issues. Patience is key; keep adding segments until the green docking hologram appears when you approach the Moonpool from a distance.
Test Your New Docking Bay
After you have completed the expansions, it is time to test your work. Pilot your Tadpole away from the base and then circle back, approaching the Moonpool at a slow, steady angle. If you have added enough space, the automatic docking system will engage. You will see the Tadpole be pulled down into the water and lifted smoothly into the dock. If the error message persists, return to your Habitat Builder and add at least one more section to the Moonpool. Continue this process until the dock accepts your vehicle. Once you have successfully docked, the system will remember the configuration, and every subsequent return will be automatic and seamless.
