Back in the day, most of the offshore stuff was single engine, single pilot. Nowadays, it is mainly multi-engine, multi-pilot. Good news for us as it means more pilots. A few of the other rules were that single engine could not take off until after sunrise and had to be on deck 30 minutes prior to sunset. Gotta get up early!
Bread and butter of the GOM Oil & Gas is still Day VFR Bell 407/206L4's. Entry pay is around $50K for a 7/7 schedule with $300 per day for days flown over schedule.