What is the difference between Underwater and In-House Underwater sensors?

The Underwater Sensor System is rated for use in water at depths greater than the In-House Underwater Sensor System. More specifically:

The Underwater Strain Transducer is waterproof to at least 300 m (~1,000 ft.) for at least 1-month. It is waterproof to 1500 m (~5,000 ft) for 2 weeks. The Underwater Piezo Electric Accelerometer is waterproof to at least 300 m (~1,000 ft.) for at least 1-month. It is also waterproof to 1500 m (~5,000 ft.) for 2 weeks. The Underwater Main Cable is waterproof to 1500 m (~5,000 ft.) for 2 weeks except for its top end that connects directly to the PDA-8G.

For the In-House Underwater Sensor System, the Strain Transducer, Piezo Electric Transducer, and Piezoresistive Accelerometer (Model K) are waterproof to 100 m for 2 weeks.