This week promises to be pivotal in the ongoing controversy over and scrutiny of the plan for two Shell-leased drill rigs to come to the Port of Seattle‘s Terminal 5 in West Seattle before heading to the Arctic Ocean.

One of those rigs, the drillship Noble Discoverer, took an unexpected – at least to observers – turn this weekend.

As noted here Thursday, Noble Discoverer is expected to stop in Everett this week. Foss Maritime has indicated that the city of Seattle’s suggestion that it’s not coming here is inaccurate, so the expectation is that it would then proceed to T-5.

We’ve been checking online vessel tracker MarineTraffic.com relatively often for any signs of the drillship coming into range – it was last “seen” by tracking signal when it was off Honolulu two weeks ago (at which time, it’s since been revealed, it failed a Coast Guard inspection).

Looking at MT very early this morning, we noticed Noble Discoverer had been in tracking range for a while starting Saturday morning, approaching the entrance to the Strait of Juan De Fuca – but then disappeared from tracking. Almost concurrently, we received a note from Robert, pointing to this online observation with a few more specifics, showing that the ship had turned around and gone back out of tracking range. Here’s what MT’s records show:

MT tracking doesn’t pick up until relatively close to the coast, so we don’t know quite where the drillship is now – just that it’s out of range, shown as having been last “seen” at 2:43 am today (our time) sailing away from the Washington coast, about 18 hours after it had become visible while sailing toward it.

Meantime, Shell’s other drill rig, the platform Polar Pioneer, has now spent three weeks in Port Angeles (where this webcam points toward it around the clock); here in Seattle, the Port Commission takes up the T-5 lease/city interpretation situation in public session Tuesday afternoon, and opponents of offshore Arctic drilling plan a series of protests here in (and off) West Seattle starting later in the week, culminating in an early-morning march from Harbor Island to T-5 one week from tomorrow .