Gathered Information:

LOA: 22.75 ft
LWL: 19.50 ft
Beam: 7.92 ft
Maximum Draft: 5.33 ft
Calculate Rectangular Portion Area:

Area=19.50 ft×7.92 ft=154.44 square feetArea=19.50 ft×7.92 ft=154.44 square feet
Calculate Keel Area:

Area of keel=Max Draft×Width of keelArea of keel=Max Draft×Width of keel
If we assume the keel is rectangular and 1.5 feet wide:
Area of keel=5.33 ft×1.5 ft=7.995 square feetArea of keel=5.33 ft×1.5 ft=7.995 square feet
Add Areas:

Total area=154.44 square feet+7.995 square feet=162.435 square feetTotal area=154.44 square feet+7.995 square feet=162.435 square feet
Finalize Calculation:

Round up the total surface area to ensure you have enough paint.
Rounded up, the total surface area is approximately 162.44 square feet.