diff --git a/.github/workflows/cache-pixi-lock.yml b/.github/workflows/cache-pixi-lock.yml
new file mode 100644
index 00000000..984d5548
--- /dev/null
+++ b/.github/workflows/cache-pixi-lock.yml
@@ -0,0 +1,50 @@
+# Adapted from https://raw.githubusercontent.com/Parcels-code/Parcels/58cdd6185b3af03785c567914a070288ffd804e0/.github/workflows/cache-pixi-lock.yml
+name: Generate and cache Pixi lockfile
+
+on:
+  workflow_call:
+    outputs:
+      cache-id:
+        description: "The lock file contents"
+        value: ${{ jobs.cache-pixi-lock.outputs.cache-id }}
+
+jobs:
+  cache-pixi-lock:
+    name: Generate output
+    runs-on: ubuntu-latest
+    outputs:
+      cache-id: ${{ steps.restore.outputs.cache-primary-key }}
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+          submodules: recursive
+      - name: Get current date
+        id: date
+        run: echo "date=$(date +'%Y-%m-%d')" >> "$GITHUB_OUTPUT"
+      - uses: actions/cache/restore@v4
+        id: restore
+        with:
+          path: |
+            pixi.lock
+          key: ${{ steps.date.outputs.date }}_${{hashFiles('pixi.toml')}}
+      - uses: prefix-dev/setup-pixi@v0.9.0
+        if: ${{ !steps.restore.outputs.cache-hit }}
+        with:
+          pixi-version: v0.56.0
+          run-install: false
+      - name: Run pixi lock
+        if: ${{ !steps.restore.outputs.cache-hit }}
+        run: pixi lock
+      - uses: actions/cache/save@v4
+        if: ${{ !steps.restore.outputs.cache-hit }}
+        id: cache
+        with:
+          path: |
+            pixi.lock
+          key: ${{ steps.restore.outputs.cache-primary-key }}
+      - name: Upload pixi.lock
+        uses: actions/upload-artifact@v4
+        with:
+          name: pixi-lock
+          path: pixi.lock
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0ee289de..69877c32 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,31 +21,36 @@ env:
   FORCE_COLOR: 3
 
 jobs:
+  cache-pixi-lock:
+    uses: ./.github/workflows/cache-pixi-lock.yml
+
   tests:
-    name: tests (${{ matrix.runs-on }} | Python ${{ matrix.python-version }})
+    name: "Unit tests: ${{ matrix.runs-on }} | pixi run -e ${{ matrix.pixi-environment }} tests"
     runs-on: ${{ matrix.runs-on }}
+    needs: cache-pixi-lock
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.10", "3.12"]
+        pixi-environment: ["test-py310", "test-py312"]
         runs-on: [ubuntu-latest, windows-latest, macos-14]
 
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: mamba-org/setup-micromamba@v2
+          submodules: recursive
+      - uses: actions/cache/restore@v4
         with:
-          environment-name: ship
-          environment-file: environment.yml
-          create-args: >-
-            python=${{matrix.python-version}}
-
-      - run: pip install . --no-deps
+          path: pixi.lock
+          key: ${{ needs.cache-pixi-lock.outputs.cache-id }}
+      - uses: prefix-dev/setup-pixi@v0.9.0
+        with:
+          cache: true
+          cache-write: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
 
       - name: Test package
-        run: >-
-          python -m pytest -ra --cov --cov-report=xml --cov-report=term
+        run:
+          pixi run -e ${{ matrix.pixi-environment }} tests -ra --cov --cov-report=xml --cov-report=term
           --durations=20
 
       - name: Upload coverage report
@@ -53,24 +58,24 @@ jobs:
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
   typechecking:
-    name: mypy
+    name: "TypeChecking: pixi run typing"
     runs-on: ubuntu-latest
+    needs: cache-pixi-lock
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: mamba-org/setup-micromamba@v2
+          submodules: recursive
+      - uses: actions/cache/restore@v4
         with:
-          environment-name: ship
-          environment-file: environment.yml
-          create-args: >-
-            python=3.12
-
-      - run: pip install . --no-deps
-      - run: conda install lxml # dep for report generation
+          path: pixi.lock
+          key: ${{ needs.cache-pixi-lock.outputs.cache-id }}
+      - uses: prefix-dev/setup-pixi@v0.9.0
+        with:
+          cache: true
+          cache-write: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
       - name: Typechecking
-        run: |
-          mypy --install-types --non-interactive src/virtualship --html-report mypy-report
+        run: pixi run typing --non-interactive --html-report mypy-report
       - name: Upload test results
         if: ${{ always() }} # Upload even on mypy error
         uses: actions/upload-artifact@v4
diff --git a/.gitignore b/.gitignore
index 4efdfe45..b8aed21d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -178,3 +178,9 @@ src/virtualship/_version_setup.py
 
 .vscode/
 .DS_Store
+
+# Ignore pixi.lock file for this project. The con of 22k lines of noise it adds to diffs is not worth
+# the minor benefit of perfectly reproducible environments for all developers (and all the tooling that would
+# be required to support that - see https://github.com/pydata/xarray/issues/10732#issuecomment-3327780806
+# for more details)
+pixi.lock
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 00000000..8af91012
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "Parcels"]
+	path = Parcels
+	url = git@github.com:Parcels-code/Parcels.git
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 1c13b28a..a8b751be 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -1,18 +1,17 @@
-# Read the Docs configuration file
-# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
-
 version: 2
-sphinx:
-  configuration: docs/conf.py
 build:
-  os: ubuntu-22.04
+  os: ubuntu-lts-latest
   tools:
-    python: mambaforge-22.9
+    python: "latest" # just so RTD stops complaining
   jobs:
-    pre_build:
-      - pip install .
-      - sphinx-build -b linkcheck docs/ _build/linkcheck
-      - sphinx-apidoc -o docs/api/ --module-first --no-toc --force src/virtualship
-
-conda:
-  environment: environment.yml
+    create_environment:
+      - asdf plugin add pixi
+      - asdf install pixi latest
+      - asdf global pixi latest
+    install:
+      - pixi install -e docs
+    build:
+      html:
+        - pixi run -e docs sphinx-build -T -b html docs $READTHEDOCS_OUTPUT/html
+sphinx:
+  configuration: docs/conf.py
diff --git a/README.md b/README.md
index b9a59e70..2444bc70 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,7 @@
 
 <!-- Badges -->
 
+[![Pixi Badge](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/prefix-dev/pixi/main/assets/badge/v0.json)](https://pixi.sh)
 [![Anaconda-release](https://anaconda.org/conda-forge/virtualship/badges/version.svg)](https://anaconda.org/conda-forge/virtualship/)
 ![PyPI - Python Version](https://img.shields.io/pypi/pyversions/virtualship)
 [![DOI](https://zenodo.org/badge/682478059.svg)](https://doi.org/10.5281/zenodo.14013931)
diff --git a/docs/contributing/index.md b/docs/contributing/index.md
index 27d6d40c..877a0f25 100644
--- a/docs/contributing/index.md
+++ b/docs/contributing/index.md
@@ -8,36 +8,75 @@ We have a design document providing a conceptual overview of VirtualShip. This d
 
 ### Development installation
 
-We use `conda` to manage our development installation. Make sure you have `conda` installed by following [the instructions here](https://docs.conda.io/projects/conda/en/latest/user-guide/install/index.html) and then run the following commands:
+```{note}
+VirtualShip uses [Pixi](https://pixi.sh) to manage environments and run developer tooling. Pixi is a modern alternative to Conda and also includes other powerful tooling useful for a project like VirtualShip. It is our sole development workflow - we do not offer a Conda development workflow. Give Pixi a try, you won't regret it!
+```
+
+To get started contributing to VirtualShip:
+
+**Step 1:** [Install Pixi](https://pixi.sh/latest/).
+
+**Step 2:** [Fork the repository](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/fork-a-repo#forking-a-repository)
+
+**Step 3:** Clone your fork with submodules and `cd` into the repository.
+
+```bash
+git clone --recurse-submodules git@github.com:YOUR_USERNAME/virtualship.git
+cd virtualship
+```
+
+```{note}
+The `--recurse-submodules` flag is required to clone the Parcels submodule, which is used for testing and development.
+```
+
+**Step 4:** Install the Pixi environment
 
 ```bash
-conda create -n ship python=3.10
-conda activate ship
-conda env update --file environment.yml
-pip install -e . --no-deps --no-build-isolation
+pixi install
 ```
 
-This creates an environment, and installs all the dependencies that you need for development, including:
+Now you have a development installation of VirtualShip, as well as a bunch of developer tooling to run tests, check code quality, and build the documentation! Simple as that.
 
-- core dependencies
-- development dependencies (e.g., for testing)
-- documentation dependencies
+### Pixi workflows
 
-then installs the package in editable mode.
+You can use the following Pixi commands to run common development tasks.
 
-### Useful commands
+**Testing**
 
-The following commands are useful for local development:
+- `pixi run tests` - Run the full test suite using pytest with coverage reporting
+- `pixi run tests-notebooks` - Run notebook tests
 
-- `pytest` to run tests
-- `pre-commit run --all-files` to run pre-commit checks
-- `pre-commit install` (optional) to install pre-commit hooks
-  - this means that every time you commit, pre-commit checks will run on the files you changed
-- `sphinx-autobuild docs docs/_build` to build and serve the documentation
-- `sphinx-apidoc -o docs/api/ --module-first --no-toc --force src/virtualship` (optional) to generate the API documentation
-- `sphinx-build -b linkcheck docs/ _build/linkcheck` to check for broken links in the documentation
+**Documentation**
 
-The running of these commands is useful for local development and quick iteration, but not _vital_ as they will be run automatically in the CI pipeline (`pre-commit` by pre-commit.ci, `pytest` by GitHub Actions, and `sphinx` by ReadTheDocs).
+- `pixi run docs` - Build the documentation using Sphinx
+- `pixi run docs-watch` - Build and auto-rebuild documentation when files change (useful for live editing)
+
+**Code quality**
+
+- `pixi run lint` - Run pre-commit hooks on all files (includes formatting, linting, and other code quality checks)
+- `pixi run typing` - Run mypy type checking on the codebase
+
+**Different environments**
+
+VirtualShip supports testing against different environments (e.g., different Python versions) with different feature sets. In CI we test against these environments, and you can too locally. For example:
+
+- `pixi run -e test-py311 tests` - Run tests using Python 3.11
+- `pixi run -e test-py312 tests` - Run tests using Python 3.12
+- `pixi run -e test-latest tests` - Run tests using latest Python
+
+The name of the workflow on GitHub contains the command you have to run locally to recreate the workflow - making it super easy to reproduce CI failures locally.
+
+**Typical development workflow**
+
+1. Make your code changes
+2. Run `pixi run lint` to ensure code formatting and style compliance
+3. Run `pixi run tests` to verify your changes don't break existing functionality
+4. If you've added new features, run `pixi run typing` to check type annotations
+5. If you've modified documentation, run `pixi run docs` to build and verify the docs
+
+```{tip}
+You can run `pixi info` to see all available environments and `pixi task list` to see all available tasks across environments.
+```
 
 ## For maintainers
 
@@ -52,5 +91,5 @@ The running of these commands is useful for local development and quick iteratio
 
 When adding a dependency, make sure to modify the following files where relevant:
 
-- `environment.yml` for core and development dependencies (important for the development environment, and CI)
+- `pixi.toml` for core and development dependencies (important for the development environment, and CI)
 - `pyproject.toml` for core dependencies (important for the pypi package, this should propagate through automatically to `recipe/meta.yml` in the conda-forge feedstock)
diff --git a/environment.yml b/environment.yml
deleted file mode 100644
index 3d7f83ef..00000000
--- a/environment.yml
+++ /dev/null
@@ -1,43 +0,0 @@
-name: ship_parcelsv4 #TODO: revert back to 'ship' before proper release...
-channels:
-  - conda-forge
-  - https://repo.prefix.dev/parcels
-dependencies:
-  - click
-  - parcels =4.0.0alpha0
-  - pyproj >= 3, < 4
-  - sortedcontainers == 2.4.0
-  - opensimplex == 0.4.5
-  - numpy >=2.1
-  - pydantic >=2, <3
-  - pip
-  - pyyaml
-  - copernicusmarine >= 2.2.2
-  - openpyxl
-  - yaspin
-  - textual
-  # - pip:
-  #     - git+https://github.com/OceanParcels/parcels.git@v4-dev
-
-  # linting
-  - pre-commit
-  - mypy
-
-  # Testing
-  - pytest
-  - pytest-cov
-  - pytest-asyncio
-  - codecov
-  - seabird
-  - setuptools
-
-  # Docs
-  - sphinx>=7.0
-  - myst-parser>=0.13
-  - nbsphinx
-  - ipykernel
-  - pandoc
-  - sphinx-copybutton
-  # - sphinx-autodoc-typehints # https://github.com/OceanParcels/virtualship/pull/125#issuecomment-2668766302
-  - pydata-sphinx-theme
-  - sphinx-autobuild
diff --git a/pixi.toml b/pixi.toml
new file mode 100644
index 00000000..15dfe87b
--- /dev/null
+++ b/pixi.toml
@@ -0,0 +1,91 @@
+[workspace]
+name = "VirtualShip"
+preview = ["pixi-build"]
+channels = ["conda-forge"]
+platforms = ["win-64", "linux-64", "osx-64", "osx-arm64"]
+
+[package]
+name = "virtualship"
+version = "dynamic" # dynamic versioning needs better support in pixi https://github.com/prefix-dev/pixi/issues/2923#issuecomment-2598460666 . Putting `version = "dynamic"` here for now until pixi recommends something else.
+license = "MIT" # can remove this once https://github.com/prefix-dev/pixi-build-backends/issues/397 is resolved
+
+[package.build]
+backend = { name = "pixi-build-python", version = "==0.4.0" }
+
+[package.host-dependencies]
+setuptools = "*"
+setuptools_scm = "*"
+
+[environments]
+test-latest = { features = ["test"], solve-group = "test" }
+test-py311 = { features = ["test", "py311"] }
+test-py312 = { features = ["test", "py312"] }
+test-notebooks = { features = ["test", "notebooks"], solve-group = "test" }
+docs = { features = ["docs"], solve-group = "docs" }
+typing = { features = ["typing"], solve-group = "typing" }
+pre-commit = { features = ["pre-commit"], no-default-feature = true }
+
+[dependencies] # keep section in sync with pyproject.toml dependencies
+python = ">=3.11"
+click = "*"
+parcels = {path="./Parcels"}
+pyproj = ">=3,<4"
+sortedcontainers = "==2.4.0"
+opensimplex = "==0.4.5"
+numpy = ">=2.1"
+pydantic = ">=2,<3"
+pyyaml = "*"
+copernicusmarine = ">=2.2.2"
+yaspin = "*"
+textual = "*"
+virtualship = { path = "." }
+
+[feature.py311.dependencies]
+python = "3.11.*"
+
+[feature.py312.dependencies]
+python = "3.12.*"
+
+[feature.test.dependencies]
+pytest = "*"
+pytest-cov = "*"
+pytest-asyncio = "*"
+seabird = "*"
+openpyxl = "*"
+
+[feature.test.tasks]
+tests = "pytest"
+
+[feature.notebooks.dependencies]
+nbval = "*"
+ipykernel = "*"
+
+[feature.notebooks.tasks]
+tests-notebooks = "pytest --nbval-lax docs/"
+
+[feature.docs.dependencies]
+sphinx = ">=7.0"
+myst-parser = ">=0.13"
+nbsphinx = "*"
+ipykernel = "*"
+pandoc = "*"
+sphinx-copybutton = "*"
+pydata-sphinx-theme = "*"
+sphinx-autobuild = "*"
+
+[feature.docs.tasks]
+docs = "sphinx-build docs docs/_build"
+docs-watch = "sphinx-autobuild docs docs/_build"
+
+[feature.pre-commit.dependencies]
+pre_commit = "*"
+
+[feature.pre-commit.tasks]
+lint = "pre-commit run --all-files"
+
+[feature.typing.dependencies]
+mypy = "*"
+lxml = "*"
+
+[feature.typing.tasks]
+typing = "mypy src/virtualship --install-types"
diff --git a/pyproject.toml b/pyproject.toml
index 6ab2e064..20036465 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -8,7 +8,7 @@ description = "Code for the Virtual Ship Classroom, where Marine Scientists can
 readme = "README.md"
 dynamic = ["version"]
 authors = [{ name = "oceanparcels.org team" }]
-requires-python = ">=3.10"
+requires-python = ">=3.11"
 license = { file = "LICENSE" }
 classifiers = [
     "Development Status :: 3 - Alpha",
diff --git a/src/virtualship/models/space_time_region.py b/src/virtualship/models/space_time_region.py
index 48ad5699..596b7896 100644
--- a/src/virtualship/models/space_time_region.py
+++ b/src/virtualship/models/space_time_region.py
@@ -1,10 +1,9 @@
 """SpaceTimeRegion class."""
 
 from datetime import datetime
-from typing import Annotated
+from typing import Annotated, Self
 
 from pydantic import BaseModel, Field, model_validator
-from typing_extensions import Self
 
 Longitude = Annotated[float, Field(..., ge=-180, le=180)]
 Latitude = Annotated[float, Field(..., ge=-90, le=90)]