diff --git a/INSTALLATION.md b/INSTALLATION.md
new file mode 100644
index 0000000..2931b4d
--- /dev/null
+++ b/INSTALLATION.md
@@ -0,0 +1,179 @@
+# Installation Guide
+
+## Dependency Management
+
+WeatherRoutingTool uses optional dependency groups to provide a flexible installation experience. This allows users to install only the dependencies they need, reducing installation time and potential conflicts.
+
+## Installation Options
+
+### 1. Minimal Installation (Recommended for beginners)
+```bash
+pip install WeatherRoutingTool
+```
+
+**What you get:**
+- Core weather routing functionality
+- Basic data processing capabilities
+- Configuration management
+- Essential scientific computing tools
+
+**Use case:** Learning weather routing, basic route optimization, or when you don't need visualization.
+
+### 2. With Visualization
+```bash
+pip install WeatherRoutingTool[viz]
+```
+
+**What you get:**
+- Everything from minimal installation
+- Route visualization and plotting
+- Map generation
+- Statistical plots
+
+**Use case:** When you need to visualize routes, weather conditions, or optimization results.
+
+### 3. With Geospatial Features
+```bash
+pip install WeatherRoutingTool[geospatial]
+```
+
+**What you get:**
+- Everything from minimal installation
+- Advanced geographic calculations
+- Land mask support
+- Geospatial data analysis
+
+**Use case:** When working with complex geographic constraints or advanced route planning.
+
+### 4. With Genetic Algorithm
+```bash
+pip install WeatherRoutingTool[genetic]
+```
+
+**What you get:**
+- Everything from minimal installation
+- Genetic algorithm optimization
+- Multi-objective optimization capabilities
+
+**Use case:** When you need advanced optimization algorithms beyond basic routing.
+
+### 5. With Data Processing
+```bash
+pip install WeatherRoutingTool[data]
+```
+
+**What you get:**
+- Everything from minimal installation
+- Large dataset processing
+- Parallel computing capabilities
+- Advanced data access
+
+**Use case:** When working with large weather datasets or need performance optimization.
+
+### 6. With External Data Download
+```bash
+pip install WeatherRoutingTool[download]
+```
+
+**What you get:**
+- Everything from minimal installation
+- Automatic weather data downloading
+- Access to external data sources
+
+**Use case:** When you need to fetch weather data from external sources automatically.
+
+### 7. Full Installation
+```bash
+pip install WeatherRoutingTool[all]
+```
+
+**What you get:** All features and dependencies.
+
+**Use case:** When you need all features or are unsure which groups you need.
+
+### 8. Development Installation
+```bash
+pip install WeatherRoutingTool[dev]
+```
+
+**What you get:**
+- All features
+- Development tools (flake8, pytest)
+- Testing framework
+
+**Use case:** For contributors and developers working on the codebase.
+
+## Combining Groups
+
+You can combine multiple groups:
+```bash
+pip install WeatherRoutingTool[viz,genetic]
+```
+
+## Upgrading Installations
+
+To add features to an existing installation:
+```bash
+pip install WeatherRoutingTool[viz]  # Adds visualization to existing installation
+```
+
+## Troubleshooting
+
+### Installation Issues
+
+1. **Cartopy installation fails on Windows:**
+   ```bash
+   pip install WeatherRoutingTool[viz] --no-binary cartopy
+   ```
+
+2. **Memory errors during installation:**
+   Use minimal installation and add groups as needed:
+   ```bash
+   pip install WeatherRoutingTool
+   pip install WeatherRoutingTool[viz]
+   ```
+
+3. **Conflicts with existing packages:**
+   Use a virtual environment:
+   ```bash
+   python -m venv wrt_env
+   source wrt_env/bin/activate  # On Windows: wrt_env\Scripts\activate
+   pip install WeatherRoutingTool[all]
+   ```
+
+### Dependency Conflicts
+
+If you encounter dependency conflicts, try:
+1. Using a fresh virtual environment
+2. Installing groups individually to identify the conflicting package
+3. Using `pip install --upgrade` to update conflicting packages
+
+## Performance Considerations
+
+- **Minimal installation** has the fastest installation time and smallest footprint
+- **Full installation** provides all features but takes longer to install
+- **Selective installation** reduces the chance of dependency conflicts
+- **Virtual environments** are recommended for all installations
+
+## Feature Requirements
+
+| Feature | Required Dependency Group |
+|---------|---------------------------|
+| Basic routing | core (included in all installations) |
+| Route plotting | viz |
+| Map generation | viz |
+| Genetic algorithm | genetic |
+| Land constraints | geospatial |
+| Large datasets | data |
+| Auto-download weather | download |
+| Image processing | image |
+
+## Migration from Previous Versions
+
+If you're upgrading from a version before dependency groups:
+1. Your existing installation will continue to work
+2. To use the new modular approach, create a fresh installation:
+   ```bash
+   pip uninstall WeatherRoutingTool
+   pip install WeatherRoutingTool[all]  # Or your preferred groups
+   ```
diff --git a/README.md b/README.md
index 72b7f47..006c4af 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,69 @@
 
 A tool to perform optimization of ship routes based on fuel consumption in different weather conditions.
 
+## Installation
+
+### Minimal Installation (Core Features)
+For basic weather routing functionality without visualization or advanced features:
+
+```bash
+pip install WeatherRoutingTool
+```
+
+### Installation with Optional Features
+
+#### With Visualization Support
+For plotting and visualization capabilities:
+```bash
+pip install WeatherRoutingTool[viz]
+```
+
+#### With Geospatial Features
+For advanced geospatial analysis:
+```bash
+pip install WeatherRoutingTool[geospatial]
+```
+
+#### With Genetic Algorithm
+For optimization using genetic algorithms:
+```bash
+pip install WeatherRoutingTool[genetic]
+```
+
+#### With Data Processing
+For large dataset processing:
+```bash
+pip install WeatherRoutingTool[data]
+```
+
+#### With External Data Download
+For downloading weather data:
+```bash
+pip install WeatherRoutingTool[download]
+```
+
+#### Full Installation
+For all features (equivalent to current installation):
+```bash
+pip install WeatherRoutingTool[all]
+```
+
+#### Development Installation
+For contributors and developers:
+```bash
+pip install WeatherRoutingTool[dev]
+```
+
+### Dependency Groups
+
+- **Core**: `numpy`, `pandas`, `xarray`, `scipy`, `pydantic`, `astropy` - Essential for basic functionality
+- **Visualization**: `matplotlib`, `seaborn`, `cartopy` - Plotting and mapping
+- **Geospatial**: `geopandas`, `shapely`, `geographiclib`, `geovectorslib`, `global_land_mask` - Advanced geographic features
+- **Data Processing**: `dask`, `datacube`, `netcdf4` - Large dataset handling
+- **Download**: `maridatadownloader` - External weather data downloading
+- **Genetic**: `pymoo` - Genetic algorithm optimization
+- **Image**: `scikit-image`, `Pillow` - Image processing
+
 Documentation: https://52north.github.io/WeatherRoutingTool/
 
 Introduction: [WRT-sandbox](https://github.com/52North/WRT-sandbox) [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/52North/WRT-sandbox.git/HEAD?urlpath=%2Fdoc%2Ftree%2FNotebooks/execute-WRT.ipynb)
diff --git a/pyproject.toml b/pyproject.toml
index d676a3f..9a5cbe8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,8 +21,70 @@ classifiers = [
 ]
 dynamic = ["dependencies"]
 
+[project.optional-dependencies]
+# Core dependencies for basic weather routing functionality
+core = [
+    "numpy",
+    "pandas", 
+    "xarray",
+    "scipy>=1.10.0",
+    "pydantic",
+    "astropy"
+]
+
+# Visualization and plotting capabilities
+viz = [
+    "matplotlib",
+    "seaborn",
+    "cartopy>0.20.0"
+]
+
+# Advanced geospatial features
+geospatial = [
+    "geopandas",
+    "shapely", 
+    "geographiclib",
+    "geovectorslib",
+    "global_land_mask"
+]
+
+# Large dataset processing and data access
+data = [
+    "dask",
+    "datacube",
+    "netcdf4"
+]
+
+# External data downloading capabilities
+download = [
+    "maridatadownloader@git+https://github.com/52North/maridatadownloader"
+]
+
+# Genetic algorithm optimization
+genetic = [
+    "pymoo>=0.6.1"
+]
+
+# Image processing features
+image = [
+    "scikit-image",
+    "Pillow"
+]
+
+# All optional dependencies (full installation)
+all = [
+    "WeatherRoutingTool[core,viz,geospatial,data,download,genetic,image]"
+]
+
+# Development dependencies
+dev = [
+    "WeatherRoutingTool[all]",
+    "flake8",
+    "pytest"
+]
+
 [tool.setuptools.dynamic]
-dependencies = { file = ["requirements.txt"] }
+dependencies = { file = ["requirements.core.txt"] }
 
 [tool.setuptools.packages.find]
 include = ["WeatherRoutingTool*"]
diff --git a/requirements.core.txt b/requirements.core.txt
new file mode 100644
index 0000000..0415220
--- /dev/null
+++ b/requirements.core.txt
@@ -0,0 +1,9 @@
+# Core dependencies for minimal WeatherRoutingTool installation
+# These are essential for basic weather routing functionality
+
+numpy
+pandas
+xarray
+scipy>=1.10.0
+pydantic
+astropy
diff --git a/test_minimal_install.py b/test_minimal_install.py
new file mode 100644
index 0000000..09ec8bf
--- /dev/null
+++ b/test_minimal_install.py
@@ -0,0 +1,119 @@
+#!/usr/bin/env python3
+"""
+Test script to verify minimal installation works correctly.
+This script tests core functionality without optional dependencies.
+"""
+
+import sys
+import traceback
+
+def test_core_imports():
+    """Test that core modules can be imported with minimal installation."""
+    print("Testing core imports...")
+    
+    try:
+        # Core dependencies
+        import numpy as np
+        import pandas as pd
+        import xarray as xr
+        from scipy import interpolate
+        import astropy.units as u
+        from pydantic import BaseModel
+        print("✓ Core dependencies imported successfully")
+    except ImportError as e:
+        print(f"✗ Core dependency import failed: {e}")
+        return False
+    
+    try:
+        # WRT core modules
+        import WeatherRoutingTool.config as config
+        import WeatherRoutingTool.routeparams as routeparams
+        import WeatherRoutingTool.weather as weather
+        print("✓ WRT core modules imported successfully")
+    except ImportError as e:
+        print(f"✗ WRT core module import failed: {e}")
+        traceback.print_exc()
+        return False
+    
+    return True
+
+def test_basic_functionality():
+    """Test basic WRT functionality."""
+    print("\nTesting basic functionality...")
+    
+    try:
+        from WeatherRoutingTool.config import Config
+        from WeatherRoutingTool.weather import WeatherCond
+        from datetime import datetime, timedelta
+        
+        # Test basic configuration
+        print("✓ Config class accessible")
+        
+        # Test weather condition creation
+        weather_cond = WeatherCond(
+            time=datetime.now(),
+            hours=24,
+            time_res=3
+        )
+        print("✓ WeatherCond creation successful")
+        
+        return True
+    except Exception as e:
+        print(f"✗ Basic functionality test failed: {e}")
+        traceback.print_exc()
+        return False
+
+def test_optional_imports_fail():
+    """Test that optional dependencies are not available in minimal install."""
+    print("\nTesting that optional dependencies are not available...")
+    
+    optional_deps = [
+        ('matplotlib', 'matplotlib.pyplot'),
+        ('cartopy', 'cartopy.crs'),
+        ('geopandas', 'geopandas'),
+        ('pymoo', 'pymoo'),
+        ('dask', 'dask'),
+        ('netcdf4', 'netCDF4'),
+    ]
+    
+    for dep_name, import_path in optional_deps:
+        try:
+            __import__(import_path)
+            print(f"⚠ Optional dependency {dep_name} is available (unexpected)")
+        except ImportError:
+            print(f"✓ Optional dependency {dep_name} not available (expected)")
+    
+    return True
+
+def main():
+    """Run all tests."""
+    print("WeatherRoutingTool Minimal Installation Test")
+    print("=" * 50)
+    
+    tests = [
+        test_core_imports,
+        test_basic_functionality,
+        test_optional_imports_fail,
+    ]
+    
+    results = []
+    for test in tests:
+        try:
+            result = test()
+            results.append(result)
+        except Exception as e:
+            print(f"✗ Test {test.__name__} failed with exception: {e}")
+            results.append(False)
+    
+    print("\n" + "=" * 50)
+    print(f"Results: {sum(results)}/{len(results)} tests passed")
+    
+    if all(results):
+        print("🎉 All tests passed! Minimal installation works correctly.")
+        return 0
+    else:
+        print("❌ Some tests failed. Check the output above.")
+        return 1
+
+if __name__ == "__main__":
+    sys.exit(main())