Lake Wylie is the closest large lake to Charlotte and its summer traffic reflects that. Swimmers off a dock or a raft-up should assume they are invisible to an approaching boat: fly a diver-down or swim flag where required, keep a spotter aboard, and stay inside the no-wake envelope near docks and coves rather than drifting toward the channel.
Two further hazards are specific to reservoirs. The pool level moves, so a sandbar that was waist-deep in July can be exposed rock in November, and submerged stumps and old channel structure sit just under the surface in places that look open. Never jump or dive into unfamiliar water here. And electricity around private docks — shore power, lifts, lighting — is worth a professional inspection; swimming directly beside an energised dock is the one risk on this lake that people consistently underestimate.
South Carolina and North Carolina each enforce their own boating and life-jacket law on their side of the state line, with the Lake Wylie Marine Commission coordinating across it. Children's life-jacket requirements differ; carry to the stricter standard and the question never arises.