It's an adaptation of the Breton Fisherman's Prayer
"Oh God, Thy sea is so great and my boat is so small," is actually all there is to the original, which is known as the Breton Fisherman's Prayer--fishermen from Brittany, a region in France. It's widely adapted and expanded on, especially when used in fleet blessings.
The Breton Fisherman's Prayer was engraved on a brass plaque and presented to President John F. Kennedy by US Navy Admiral Hyman Rickover. The admiral would subsequently present the same type of plaque to all new commanders of Polaris submarines. I suspect that someone on the board of whatever YC your plaque is from who may have served on a Polaris thought that was such a neat idea that they adopted it as well as adapted it for their members at that year's annual fleet blessing.