Thank you, Kevin. That distinction is helpful. The current prototype provides compass navigation only, but our planned next step is to add current and maximum depth as a simple depth-gauge feature, before considering more advanced dive functionality. We understand that adding depth information does not automatically establish eligibility for either entitlement, and that App Review makes the final determination. We will contact them for formal guidance on the appropriate entitlement and background category for that functionality, including use below 6 meters. Is there a recommended channel for requesting this guidance from App Review before submission?

Thank you for the suggestions, especially the diagnostic logging profile. One clarification: the reported accuracy remains around 89° even on land, while stationary, when the Watch heading agrees with an analog compass worn on the opposite arm. This happens outside the water activity as well. My current logger truncates headingAccuracy to an integer, so I will capture the full raw value and timestamped heading samples before testing .maritime separately. Have you observed this persistent accuracy value specifically on Apple Watch? I’m trying to understand whether it indicates a calibration issue or has a watchOS-specific interpretation. If the heading reversal happens again, I will also capture the location diagnostics and a sysdiagnose as you suggested.

Thank you, Kevin. This is very helpful and clarifies the distinction I was trying to understand. For this particular app, I don't need depth, pressure, or temperature data at all. The goal is simply to build an underwater compass that remains frontmost and operational during a recreational scuba dive, using heading data and physical controls while Water Lock is active. I'll proceed with the Shallow Depth and Pressure entitlement and test the behavior on an Apple Watch Ultra 2 during an actual dive below 6 meters. I'm particularly interested in seeing what happens when the watch transitions to pastMaxDepth: whether the extended runtime session and compass continue operating normally, and how intrusive the maximum-depth warnings are. I'll report my findings here after testing it underwater, since this may also be useful to other developers considering similar apps. Thanks again for the clarification!