We haven't yet heard whether the Feds will affirm the 2008 Chukchi Sea lease sale that would allow Shell to drill in the Arctic this summer—the decision is expected any day now—but we do know that Shell's rigs are already on the move toward the Pacific Coast.

Can we guess when they'll arrive in Seattle?

Port commissioner Bill Bryant told the Evergreen Women Republican's Club last week that Shell's first rig will arrive in early April, but we hardly know anything more than that. When in early April? And which rig? If protesters really do plan on bringing their kayaks out to meet the ships, they'll need to find out—which is very likely the reason Shell has not disclosed any of this information itself. (And why lawyers for the port and Foss Maritime wouldn't say so in King County Superior Court recently.)

But with a little deduction, we can track Shell's fleet.

Fuel Fix reports:

Even if Jewell okays the sale, Shell must secure drilling permits and other regulatory approvals as part of its quest to return to the Chukchi Sea north of Alaska, where it drilled the first part of one well into its Burger prospect in 2012.

The company isn't waiting on the approvals to mobilize its fleet of drilling rigs and support vessels.

Both of Shell's contracted drilling rigs — the drillship Noble Discoverer and the Polar Pioneer, a Transocean semi-submersible drilling rig — are now traveling through waters near the Philippines en route to Seattle, where they are sure to get a chilly reception from local Arctic drilling opponents.

According to Noble Corporation's latest fleet status report, dated March 12, the drill ship Noble Discoverer is "in transit," and the next update is expected on April 9. The Polar Pioneer, meanwhile, is currently being carried by the Blue Marlin, a heavy lift vessel transporting it across the ocean. The Blue Marlin's last automatic identification system (AIS) update from March 13 put it just off the coast of the Philippines in the Sulu Sea.

The other latest development: Greenpeace has deployed its own ship, the Esperanza, a recycled Russian firefighting vessel commissioned in the '80s, to stalk Shell's fleet on its trip across the Pacific. The Esperanza is sailing through the waters of the Marshall Islands, and Laura Kenyon, a Greenpeace campaigner onboard, says the ship is now behind the Polar Pioneer. Greenpeace saw the Noble Discoverer earlier in their trip; it traveled next to the Blue Marlin for a bit before it fell behind, Kenyon says.

More on that later. We'll keep you abreast of the status reports, and in the meantime please enjoy this under-appreciated hit from Rockapella.

This post has been updated.