To quote the Nautical Research Guild's summary of the history of this vessel:
"Arnold regrouped his fleet and slipped past the British fleet in a desperate attempt to escape. However, they caught the retreating Continental force on October 13th, at Split Rock near Crown Point. Arnold managed to beach and destroy four of the galleys and his own flagship, Congress, while most of the remaining ships escaped upriver. Washington, at the rear of the van, was captured by the enemy; she struck her colors, as Arnold reported later, "... after receiving a few broadsides." After her capture Washington was repaired and put into British service on the lake. It was during this period that her lines were taken off."
You can find the NRG's description and an amazing guide to scratch-building a model of the galley (by Jeff Staudt) here:
http://www.thenrg.org/the-galley-washington.php
And here is Langton's 1:1200 model:
Here for size comparison the model is seen with several other Langton kits. To her left is a small schooner with a pivot gun, to her right a gunboat. To the rear is a 24 gun frigate.