On its registration certificate it gives the engine as a W670 series built by Continental.
https://en.wikipedia.org/wiki/Continental_R-670
Single engine over water? Many an aviator spends/spent thousands of hours over water, single engine, supporting commercial endeavours. My case off shore oil, and often wondered how good Mr. Lycoming had done his job when looking down as wave tops were whipped into spume by winds at times 60 knots plus.