Although Labs are commonly considered to be water lovers and excellent swimmers, this isn’t always the case. Most need, at least, a little teaching and encouragement before they’re confident enough to play in the water. Teach your Lab to swim while they’re still a puppy in order to grow that confidence at an early age.
Remember – never force your dog into the water as this could lead them to develop a hard-to-overcome aversion to it.
Your best bet is to allow your Lab to learn at their own pace and let them embrace swimming in their own time.