Next Wave is an iOS app that helps wake surfers and foilers catch their perfect wave on Lake Zurich by providing real-time boat schedules and smart notifications.
- Arc42 Architecture Documentation - Complete architecture documentation with diagrams and technical details
- User Stories & Acceptance Criteria - All 47 user stories with acceptance criteria and release planning
- API Documentation - Backend API endpoints and integration details
- Download: Get Next Wave from the App Store
- Add Favorites: Select up to 5 favorite ferry stations
- Get Notifications: Set alerts 3, 5, 10, or 15 minutes before waves
- Catch Waves: Head to the water at the perfect time! 🌊
For detailed technical documentation, see Arc42 Documentation.
- 🌊 Real-time boat schedules for Swiss lakes
- 🔔 Smart notifications (3, 5, 10, or 15 minutes before waves)
- ⭐ Favorite stations (up to 5)
- 📍 Nearest station detection with GPS
- ⌚️ Apple Watch app with complications and widgets
- 🚢 Ship names & wave ratings (1-3 waves) for Lake Zurich
- 📊 Wave analytics with best session recommendations
- 🌅 Daylight phase icons (sun/twilight/moon) for each departure
- ☀️ Daylight integration for optimal session planning
- 🔍 Albis-Class filter for best waves
- 🌤️ Real-time weather (temperature, wind, pressure)
- 🌡️ Water temperature for all Swiss lakes (via Alplakes API from Eawag)
- 📈 Temperature forecasts for the next 2 days
- 💧 Water level indicators
- 🤸 Wetsuit recommendations based on conditions
- 🗺️ Interactive map with OpenStreetMap
- 📱 Light & Dark Mode with device flip gesture
- 📤 Share waves via WhatsApp, Messages, or Mail
- 🛡️ Safety guidelines integrated
- 💬 Fun messages with personality
For complete feature details and technical specifications, see the Arc42 Documentation.
- Download from the App Store
- Grant location permissions (optional, for nearest station feature)
- Grant notification permissions (optional, for wave alerts)
- Add your favorite stations
- Start catching waves! 🌊
- Clone the repository
git clone https://github.com/pfederi/Next-Wave.git
- Open
Next Wave.xcodeprojin Xcode - Create a
Config.swiftfile with your API keys:struct Config { static let openWeatherApiKey = "YOUR_API_KEY" }
- Build and run the project
For detailed architecture and technical information, see the Arc42 Documentation.
- Select a Station: Choose from favorites or browse all Swiss lakes
- View Departures: See upcoming boat departures with ship names and wave ratings
- Check Weather: View temperature, wind, and wetsuit recommendations
- Set Notifications: Tap the bell icon to get alerted before waves arrive
- Analyze Sessions: Use the analytics view to find the best surf sessions
- Nearest Station: Enable in settings to automatically show closest station
- Albis Filter: Flip device in departure view to show only best waves
- Share Waves: Tap share button to invite friends via WhatsApp, Messages, or Mail
- Apple Watch: Install watch app for wrist-based departure times
For detailed usage scenarios and workflows, see the Arc42 Documentation - Runtime View.
- No tracking or analytics
- No personal data collection
- All data stays on device
- Location data is only used to show nearest station and your position on the map and is never stored or shared
- Location access can be denied without losing core app functionality
Next Wave aggregates data from various public sources:
- Ferry Schedules: transport.opendata.ch - Swiss public transport API
- Ship Assignments: ZSG (Zürichsee-Schifffahrtsgesellschaft) - Lake Zurich ship deployment data
- Water Temperature & Levels: MeteoNews - Swiss lake water data
- Weather Data: OpenWeather - Weather forecasts and conditions
- Sun Times: Sunrise-Sunset.org - Sunrise, sunset, and twilight data
- Maps: OpenStreetMap contributors - Map tiles and geographic data
We are grateful to these services for providing public access to their data.
The app requests location access to:
- Show your position on the map
- Enable the location tracking button
- Find the nearest station from all available ferry stations
You can use the app without granting location access. In this case:
- Your position won't be shown on the map
- The location tracking button will be disabled
- The nearest station feature will not work (you can still use favorite stations)
Next Wave offers two flexible ways to get departure information:
- Add up to 5 frequently used stations as favorites
- Get departure times for all your favorite stations
- Perfect for regular commuters with fixed routes
- Enable "Use nearest station for Widget" in app settings
- Automatically shows departures for the station closest to your current location
- Calculates nearest station from ALL available ferry stations (not just favorites)
- Perfect for travelers and explorers discovering new spots
- Works even if the nearest station is not in your favorites
- Watch App: Shows departures for favorites or nearest station
- Smart Fallback: If nearest station has no departures, automatically falls back to favorites
- Helpful Messages: Clear instructions when no favorites are set or nearest station is disabled
-
NextWave Widget: Shows your next boat departure
- Available in Small, Medium, Large, and Extra Large sizes
- Displays station name, departure time, route, and direction
- Visual indicators for nearest station or favorite station
- Deep link support to open app at specific station
-
NextWave - Next 3 Widget: Shows your next 3 boat departures
- Available in Medium and Large sizes
- Compact list view of upcoming departures
- Perfect for planning your session timing
-
Widget Modes:
- Favorite Station Mode: Shows departures from your first favorite
- Nearest Station Mode: Automatically shows closest station
- Configurable in app settings
- Complications for all watch faces
- Circular, rectangular, and inline styles
- Real-time departure information on your wrist
- Synchronized with iPhone settings
For questions or issues, please create an issue in the repository.
The app uses a JSON schedule file with the following structure. Note that coordinates are required for map display:
{
"lakes": [
{
"name": "Lake",
"operators": [
"Operator"
],
"stations": [
{
"name": "Station Name",
"uic_ref": "8503651",
"coordinates": {
"latitude": 47.218035,
"longitude": 8.776638
}
},
{
"name": "Station Name",
"uic_ref": "8503682",
"coordinates": {
"latitude": 47.218035,
"longitude": 8.776638
}
}
]
},
]
}
To find the name and especially the station ID, use the tool https://overpass-turbo.eu/ Search for the lake on the map on the right and make it completely visible. enter the following query in the console on the left:
node
[amenity=ferry_terminal]
({{bbox}});
out;
All ship stations are displayed. Clicking on the station opens a window where you can find the station ID, the name of the station and the coordinates. uic_name and uic_ref. These values are entered in the JSON file.
You can check whether the station is available in the API via https://transport.opendata.ch/v1/locations?query=[uic_ref]. The link above is for Switzerland. For other countries, you have to find another api to find departure times.
- Puppeteer-Based Scraping: Advanced web scraping using headless Chrome to handle dynamic AJAX content
- Multi-Day Data Fetching: Correctly loads ship assignments for today and next 2 days by simulating date picker clicks
- Intelligent Caching System: Three-layer caching strategy (API cache, URLSession cache, in-memory cache)
- Zero Loading Flicker: Ship names appear instantly from cache without "Loading..." indicators
- Single UI Update: All data (weather + ship names) loaded in background before single smooth UI update
- Performance: 24-hour client-side cache eliminates redundant API calls, dramatically improving app responsiveness
- CoreMotion Integration: Uses device motion sensors to detect 180° flip gestures
- Smart Gesture Recognition: Detects roll rotation with tolerance for natural device handling
- Debounce Logic: 3-second cooldown prevents accidental repeated triggers
- State Management: Tracks initial orientation and reset states for reliable detection
- Theme Toggle: Seamlessly switches between light and dark mode on device flip
- Advanced Location Processing: Uses CoreLocation to find the geographically closest ferry station
- Comprehensive Station Database: Searches through ALL available stations across multiple Swiss lakes
- Intelligent Departure Loading: Automatically fetches departure data for nearest station even if not in favorites
- Fallback System: Gracefully falls back to favorite stations if nearest station has no departures
- Real-time Synchronization: Coordinates between iOS app, Apple Watch, and widgets via shared data containers
- App Groups: Seamless data sharing between main app, Watch app, and widgets
- WatchConnectivity: Real-time synchronization of favorites and settings between iPhone and Apple Watch
- Smart Caching: Optimized caching system to minimize API calls while ensuring fresh data
- Background Updates: Intelligent background refresh with adaptive timing based on next departure
- JSON-Based Configuration: Centralized schedule period data for all Swiss lakes
- Automatic Period Detection: Real-time detection of active schedule periods based on current date
- Smart Countdown System: Calculates days until next schedule change with personalized messages
- Season-Aware Messaging: Context-aware messages based on transition type (summer/winter/spring/autumn)
- Multi-Lake Support: Handles different schedule periods for 15+ Swiss lakes simultaneously
- First Launch Detection: UserDefaults-based system to show safety rules on initial app launch
- Modal Presentation: SwiftUI-based modal with comprehensive safety information
- Persistent Access: Safety rules accessible anytime via settings
- Community Integration: Deep links to external safety resources
- VesselAPI Service: Dedicated Swift service for fetching ship assignments
- Async/Await Pattern: Modern Swift concurrency for non-blocking API calls
- Date-Based Caching: Cache key format:
YYYY-MM-DD_CourseNumber - Parallel Loading: Ship names loaded asynchronously after initial departure data
- UI Updates: Progressive enhancement - departures show immediately, ship names appear when loaded
- 3-Day Window: Only fetches ship names for departures within next 72 hours
- Lake Detection: Automatically identifies Lake Zurich stations by ID prefix (85036)
- Wave Icons: Dynamic icon selection based on ship name and wave rating database
- OpenWeather API: RESTful API integration for weather forecasts
- Async Data Loading: Non-blocking weather data fetching using Swift async/await
- Wind Chill Integration: Uses
feels_liketemperature from OpenWeather for accurate wetsuit recommendations - Pressure History Tracking: 6-hour rolling window for pressure trend calculation
- Smart Preloading: Weather data preloaded for all favorite stations at app launch
- Parallel Requests: TaskGroup-based concurrent loading for multiple stations
- Per-Wave Weather: Individual weather data for each departure time
- Forecast Matching: Finds closest forecast time to each departure
- Unit Conversion: Automatic conversion from m/s to knots for nautical use
- Weather Codes: Comprehensive mapping of OpenWeather condition codes to SF Symbols
- Error Handling: Graceful degradation when weather data unavailable
- Quiksilver Reference Table: Based on professional wetsuit thickness recommendations
- Water Temperature Based: Primary factor for wetsuit selection
- Wind Chill Consideration: Uses "feels like" temperature (wind chill) for more accurate recommendations
- 30°C Rule: If air temperature + water temperature < 30°C, recommends one size thicker
- Temperature Ranges:
- 23°C+: No wetsuit needed
- 18-23°C: 0.5-2mm (shorty)
- 15-18°C: 3/2mm
- 12-15°C: 4/3mm
- 10-12°C: 5/4mm
- 1-10°C: 6/5mm (winter wetsuit)
- Smart Algorithm: Adjusts recommendation based on combined air and water temperature
- Visual Display: Shows thickness in millimeters with figure icon
- Interactive Legend: Tap weather line to see detailed explanation of wetsuit recommendations
- Custom SwiftUI Share Sheet: Purpose-built share interface with WhatsApp, Messages, and Mail
- Platform-Specific Integration:
- WhatsApp: Direct URL scheme integration (
whatsapp://send?text=) - Messages: Native
MFMessageComposeViewControllerfor full text support - Mail: URL scheme with proper encoding (
mailto:?body=)
- WhatsApp: Direct URL scheme integration (
- Smart Text Generation: Dynamic share text with randomized intro messages
- Comprehensive Data: Includes all relevant wave and weather information
- Emoji Support: Full emoji support across all platforms including Mail
- URL Encoding: Proper encoding for special characters and line breaks
- State Management: SwiftUI state variables for sheet presentation
- Conditional Display: Share button only visible for future departures
- Weather Legend Modal: SwiftUI modal with detailed explanations of all weather data points
- Ship Database: Hardcoded list of Albis-Class ships (MS Albis, EMS Uetliberg, EMS Pfannenstiel)
- Real-Time Filtering: Instant filtering of departure list based on ship names
- State Management: Published property for reactive UI updates
- Haptic Feedback: UINotificationFeedbackGenerator for activation, UIImpactFeedbackGenerator for deactivation
- Visual Indicators: Orange banner with filter status in departure list
- Gesture Integration: Connected to device flip gesture in departure view context
The app uses various systems for collecting ship data and calculating wave characteristics:
- Automatically extracts technical data of all ZSG ships
- Collects information like length, width, displacement etc.
- Calculates based on technical data:
- Maximum wave height (m):
H = 0.04 * D * v² / (L * B) - Wave length (m):
λ = 2π * v² / g - Wave period (s):
T = √(2π * λ / g) - Wave velocity (m/s):
c = λ / T - Wave energy (J/m²):
E = (1/8) * ρ * g * H² - Wave power (W/m):
P = E * c - Impact force (N/m²):
F = ρ * g * H * (c²/2)
- Maximum wave height (m):
Where:
- D = Displacement [t]
- v = Velocity [m/s]
- L = Length [m]
- B = Beam width [m]
- g = Gravitational acceleration (9.81 m/s²)
- ρ = Water density (1000 kg/m³)
- H = Wave height [m]
- λ = Wave length [m]
- T = Wave period [s]
- c = Wave velocity [m/s]
Additional factors:
- Froude length number:
Fr_L = v / √(g * L) - Froude depth number:
Fr_h = v / √(g * h) - Reynolds number:
Re = (L * v) / ν- ν = Kinematic viscosity (1.0e-6 m²/s)
The calculations consider:
- Ship length and width
- Displacement
- Speed (18 km/h)
- Water depth (10m default)
- Froude and Reynolds numbers
-
Input Data for each ship:
- Technical data from scraper (length, width, displacement)
- Constant values:
- Speed: 18 km/h (5 m/s)
- Water depth: 10m
- Water density: 1000 kg/m³
-
Calculation Steps: a) Calculate maximum wave height (H) b) Derive wave energy (E) and impact force (F) c) Compare with thresholds:
- Energy: <150 J/m² → 1 wave, 150-250 J/m² → 2 waves, >250 J/m² → 3 waves
- Force: <45000 N/m² → 1 wave, 45000-55000 N/m² → 2 waves, >55000 N/m² → 3 waves d) Final rating is the higher of both values
-
Example Calculation MS Panta Rhei:
- Length: 56.6m, Width: 10.7m, Displacement: 382t
- Wave height: H = 0.63m
- Wave energy: E = 488 J/m² → 3 waves
- Impact force: F = 77347 N/m² → 3 waves
- Result: 3 waves
-
Example Calculation MS Bachtel:
- Length: 33.3m, Width: 6.3m, Displacement: 64t
- Wave height: H = 0.31m
- Wave energy: E = 114 J/m² → 1 wave
- Impact force: F = 37409 N/m² → 1 wave
- Result: 1 wave
-
Strong waves (3): MS Panta Rhei, MS Albis, EMS Uetliberg, EMS Pfannenstiel
- High wave energy (>250 J/m²)
- High impact force (>55000 N/m²)
-
Medium waves (2): MS Wädenswil, MS Limmat, MS Helvetia, MS Linth, DS Stadt Zürich, DS Stadt Rapperswil
- Medium wave energy (150-250 J/m²)
- Medium impact force (45000-55000 N/m²)
-
Light waves (1): MS Bachtel, MS Säntis, and all other ships
- Low wave energy (<150 J/m²)
- Low impact force (<45000 N/m²)
Execution: python3 scripts/vesseldata.py
Saves data to schiffsdaten.csv
- Vercel-based API: Serverless function for real-time ship deployments
- Puppeteer Web Scraping: Uses headless Chrome to handle dynamic AJAX-loaded content
- Date Picker Automation: Simulates clicking "Next Day" button to load data for each day
- 3-Day Forecast: Fetches ship assignments for today and the next 2 days
- Smart Caching: Daily cache updates with automatic refresh at midnight (Swiss time)
- Client-Side Caching: 24-hour HTTP cache headers for optimal performance
- Data Structure: Returns daily deployments with ship-to-course mappings
- Error Handling: Graceful fallback if data unavailable for specific days
- Currently Lake Zurich Only: ZSG network (station IDs starting with 85036)
- Endpoint:
/api/ships - Response Format:
{ "dailyDeployments": [ { "date": "2025-10-23", "routes": [ { "shipName": "MS Panta Rhei", "courseNumber": "1" } ] } ], "lastUpdated": "2025-10-23T08:00:00.000Z" } - Integration: iOS app queries API and caches results per date and course number
- Performance: Minimal API calls through intelligent client-side caching
- Vercel-based API: Serverless function for real-time water temperature and water level data
- Web Scraping: Automatically scrapes meteonews.ch for Swiss lake data
- Daily Updates: Data refreshed once per day at first request
- Smart Caching: 24-hour cache to minimize API calls and server load
- Coverage: 30+ Swiss lakes including all major lakes
- Endpoint:
/api/water-temperature - Response Format:
{ "lakes": [ { "name": "Zürichsee", "temperature": 14, "waterLevel": "405.96 m.ü.M." } ], "lastUpdated": "2025-10-29T08:00:00.000Z", "debug": { "currentSwissTime": "29.10.2025, 09:00:00", "lakesCount": 32 } } - Water Level Processing:
- App calculates difference from historical average levels
- Displays as "+X cm" or "-X cm" for easy interpretation
- Reference levels stored in
api/lake-water-levels.json - Helps foilers assess water depth and conditions
- Integration: iOS app caches data for 24 hours matching backend update frequency
- Performance: Single daily fetch per device, efficient data delivery
Have an idea for improving Next Wave? We're always open to suggestions from the community! Whether it's new features, usability improvements, or support for additional lakes - we'd love to hear from you. Feel free to open an issue on GitHub to discuss your ideas or contribute directly through a pull request.
Some ideas that have been suggested:
- Link to Foil Mates and vice versa for nearby spots
Note: International support is currently out of scope for this project. Feel free to fork the repository and create a version for your specific country!
Contributions are welcome! Please feel free to submit a Pull Request. Kanban Board is here: https://github.com/users/pfederi/projects/1
This project is licensed under the MIT License - see the LICENSE file for details.
Join our community: Pumpfoiling Community
Always maintain a safe distance from boats and follow local water safety regulations. Never surf directly behind vessels.
- Thanks to all beta testers
- Special thanks to Alex for all your good ideas and testing
- Special thanks to Nils Mango for the favorite and nearby station feature requests
- Map data © OpenStreetMap contributors
- Special thanks to the Lake boat operators - We would be delighted if you step on the gas a little more while departing from the dock.