# CMWaterSubmersionManager An object for managing the collection of pressure and temperature data during submersion. ``` class CMWaterSubmersionManager ``` ## Overview Use this class to receive live depth, water pressure, and water temperature data on Apple Watch Ultra. Start by assigning a usage description using the key in your app target’s information property list. You also need to include an entitlement to access the live submersion data. To access data for dives with a maximum depth of 6 m, add the Shallow Depth and Pressure capability to your app. For more information, see . To enable a maximum depth of 40 m, you must apply for the full Submerged Depth and Pressure entitlement. For more information, see [Express interest in the Submerged Depth and Pressure API](https://developer.apple.com/contact/request/submerged-depth-pressure-api/). > Note: > As the wearer approaches the maximum depth, the system sends a measurement with an ``doc://com.apple.coremotion/documentation/CoreMotion/CMWaterSubmersionMeasurement/DepthState/approachingMaxDepth`` submersion state. When they pass the maximum depth, it sends a ``doc://com.apple.coremotion/documentation/CoreMotion/CMWaterSubmersionMeasurement/DepthState/pastMaxDepth`` state, and if they continue to descent past the maximum depth, it sends a ``doc://com.apple.coremotion/documentation/CoreMotion/CMWaterSubmersionMeasurement/DepthState/sensorDepthError`` state. Next, check whether submersion data is available. ```swift guard CMWaterSubmersionManager.waterSubmersionAvailable else { return false } ``` If the [`waterSubmersionAvailable`](/documentation/CoreMotion/CMWaterSubmersionManager/waterSubmersionAvailable) property is , instantiate a [`CMWaterSubmersionManager`](/documentation/CoreMotion/CMWaterSubmersionManager) object and assign a delegate. ```swift // Instantiate the submersion manager. submersionManager = CMWaterSubmersionManager() // Assign the submersion manager delegate. submersionManager.delegate = self ``` Your delegate then begins receiving updates from the system. For more information, see [Accessing submersion data](/documentation/CoreMotion/accessing-submersion-data). ## Topics ### Setting the delegate [`var delegate: (any CMWaterSubmersionManagerDelegate)?`](/documentation/CoreMotion/CMWaterSubmersionManager/delegate) The object that receives updates about submersion data and events. ### Checking availability and authorization [`class var waterSubmersionAvailable: Bool`](/documentation/CoreMotion/CMWaterSubmersionManager/waterSubmersionAvailable) A Boolean value indicating whether the current device supports the submersion manager. [`class var authorizationStatus: CMAuthorizationStatus`](/documentation/CoreMotion/CMWaterSubmersionManager/authorizationStatus) A value indicating whether the app has user authorization to receive submersion data. ### Accessing the maximum depth [`var maximumDepth: Measurement?`](/documentation/CoreMotion/CMWaterSubmersionManager/maximumDepth) The maximum depth supported by the water submersion manager. ## Relationships ### Conforms To [`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible) [`CVarArg`](/documentation/Swift/CVarArg) [`Hashable`](/documentation/Swift/Hashable) [`Equatable`](/documentation/Swift/Equatable) [`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol) [`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible) ### Inherits From [`NSObject-swift.class`](/documentation/ObjectiveC/NSObject-swift.class) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)