Archaeologists Move 'Britain's oldest yacht'

Pretty modern lines for 1789, (everything old is new and vise a versa) Think Plumb bow's. The framing and garboard planks look like an early mahogany run about of the 1900's with the exception of the full keel . lapstrake and I would presume iron fastened? Curious what wood she's built out of and to what scantlings? 1820 was the last time this vessel had seen the light of day? That very well could be the answer to my question, Stored in a nice cool dry environment for 200 years. either way , its quite a find and amazing that its in the shape its in.