In a large, 12-quart stock pot, stir together water, honey, and light brown sugar until dissolved. Rinse ham and lower it into in the stock pot, adding additional water, if needed, to just cover the ham. (If a corner sticks out of the water on a very large ham, this is ok.)
Bring to a boil over medium-high heat. Reduce heat to low to just maintain a bubble, and simmer, partially covered, until thickest portion of the ham registers 125-degrees F on an instant-read thermometer. Plan on about 15-20 minutes per pound.
Glaze and Roast the Ham
While the ham is simmering, stir together all of the glaze ingredients in a high-sided saucepan. Bring to a simmer and cook over low heat, stirring frequently, until sugars are dissolved and glaze is thickened slightly, about 10 minutes.
Preheat oven to 400 degrees F. Line a baking sheet or roasting pan with foil and fit it with a rack.
Carefully remove ham from the cooking liquid. (I like to pour some of the water into the sink before lifting the ham out with two turkey forks.) Discard remaining liquid.
Place the ham on the prepared rack and score by using a sharp knife to cut a shallow diamond pattern into the fat, spacing the cuts about 1-inch apart.
Brush the entire exterior of the ham with the glaze. Roast for 10 minutes. Add a second coat of glaze and roast for an additional 10 minutes. Brush the ham with a third and final coat of glaze, roasting the ham for 10 more minutes, or until the internal temperature reaches 135-138 degrees F.*
Remove ham from oven, tent with foil, and let rest for 15 minutes (internal temperature will rise 5 degrees during this time to 140). Transfer ham to a cutting board and carve against the grain into 1/8 to 1/4-inch thick slices.
*If desired, you can caramelize the glaze further by broiling it for 5 minutes at the end of the roasting time. Keep a careful eye so that the sugars don't burn.