In a largepot, bring water, Old Bay seasoning, and salt to a boil over high heat. Addcorn, reduce heat to medium-high so that water is at a low boil, and cook for 4minutes.
Add potatoesand kielbasa and cook until potatoes are almost tender when pierced with thetip of a small knife, about 5 minutes. Add butter and garlic. Increase heat tohigh until boiling, then reduce heat so that mixture bubbles gently. Cook for 15 minutes more.
Add lemonsand shrimp to pot, pushing them down into liquid so they are mostly submerged(do not stir). Cover pot and cook until shrimp are opaque throughout, about 5minutes.
Transfercontents of pot to a large bowl or platter with slotted spoon. Let rest for 10minutes, then serve immediately.