As an heir to a large fortune, he looked forward to financial plain sailing.
Origin
1800-10
Examples from the web for plain sailing
Not that it was plain sailing by any manner of means.
But it will not all be plain sailing for the school.
British Dictionary definitions for plain sailing
plain sailing
noun
1.
(informal) smooth or easy progress
2.
(nautical) sailing in a body of water that is unobstructed; clear sailing Compare plane sailing
Idioms and Phrases with plain sailing
plain sailing
Easy going; straightforward, unobstructed progress. For example, The first few months were difficult, but I think it's plain sailing from here on. Alluding to navigating waters free of hazards, such as rocks or other obstructions, this term was transferred to other activities in the early 1800s.