Snorkeling
Yes, whales can snorkel! Read this observer's story to think about why:

"Our whale watch vessel spotted two snorkeling Gray Whales. The whales were only surfacing briefly to exhale a small puff of a blow before immediately diving again, sometimes only showing the blowholes at the surface. We suspect this may have been a cow and calf pair, but couldn’t be certain because of this elusive behavior. Gray Whales can be very stealthy while traveling through Monterey Bay to avoid detection by Killer Whales." —Katie Dunbar, Monterey Bay Whale Watch