I spent approximately 30 charter days/nights on a 2004 Ben 331. No
Sniffer was present, nor does my 2006 Ben 343 have a sniffer. As Gunni mentioned, keep the stove on and turn the gas solenoid circuit breaker off to burn off the gas remaining in the line between the tank solenoid and stove. Be sure to turn the gas knobs off on the stove after the gas in the line is burned down. I also like to take it a step further when sleeping aboard or away from the boat by turning the gas valve off on the tank.