Took a 10 min ride to the fuel dock the other day, and noticed the starboard oil pressure gauge was only reading less than 20 psi (port was at 40psi, where they both usually are). We were cruising at around 3400-3600 rpm, both engines seemed to be running great, and synchronized. Throttled down into the no wake zone, and the gauge was at 0. No smoke, no noises, engines synchronized. Fueled up, checked the oil (both clean and in the OK zone), and bilge (no signs of oil or anything abnormal). Started the engines back up and the gauge never moved off 0. Engines ran fine again on the way back. I think it’s probably a problem with the gauge, sender, or wiring in between, but wondering if anyone has any other ideas or suggestions?