If your friend told you needed a catheter as a PADI open water diver, he was pulling your.. er.. 'catheter'
If you are diving on air, the maximum depth you could go to would be 50 metres, and the maximum dive time will probably be less than 20 minute surface to surface to avoid going into decompression.
A technical diver undergoing deep dives with several hours of decompression on mixed gases may need a catheter (or a nappy!) for basic reasons, put a sports diver diving within the capabilities of PADI OW diver which will rarely be more than an hour's duration should be able to hold his water!
Think you were 'had'!