@Jen - I can call Tandem and ask them if that might help you? The water activities you mention definitely seem to fall under what the pump is listed for in terms of water.
That is (kinda) funny about the taped-up Ping. We were going to put duct tape around the case of our Animas Ping to provide structural support for where it was cracking (by the battery case). But then we selected the Tandem X2 and it all processed very fast so we didn’t need to go that route.
Note the following provides a reason why the system would no longer be watertight and under warranty which strongly implies that if such action (ie - cracking open the case) is NOT done then the system IS under warranty for water. Implied but not stated. At least here.
DO NOT open or attempt to repair your System. The System is a sealed device that should be opened and repaired only by Tandem Diabetes Care, Inc. Modification could result in a safety hazard. If your System seal is broken, the System is no longer watertight and the warranty is voided.
Also (same link) they talk about being in a pool. Again, strongly implied it is perfectly acceptable.
Wireless communication does not work well through water so the range is much less if you are in a pool, bathtub, or on a water bed, etc.
The t:slim Insulin Pump is watertight to a depth of 3 feet for up to 30 minutes (IPX7 rating). If your t:slim Pump has been submerged, check your pump for any signs of fluid entry. If there are signs of fluid entry, disconnect the set from your body, and contact Tandem Diabetes Care Customer Technical Support at 1-877-801-6901.
Your t:slim Pump is a sealed device that should be opened and repaired only by the manufacturer. If your t:slim Pump seal is broken, the warranty is voided and the pump is no longer watertight.