Blue Planet II, premiering this Saturday on BBC America, is one of those astounding TV events to make special plans to watch, record, and treasure. I can’t quite wrap my head around the new technology, and infinite patience, that allowed the filmmakers to catch such glorious, jaw-dropping images and events. BBC America is doing its best to get viewers involved in advance, by repeating, in daily marathons, its best nature documentary series of this century to date. Yesterday, the network repeated the original Blue Planet miniseries, from 2002. Today, beginning at 6 a.m. ET and again at 6:50 p.m. ET, it’s showing all episodes of its Planet Earth nature documentary series from 2007. And it’s actually better than the first time around – because back then, Discovery made the bone-headed, xenophobic decision to replace the narration by Sir David Attenborough with new narration recorded by Sigourney Weaver. Now, I love Sigourney as much as the next guy – but not when the next guy is the premier nature documentarian on the planet. Tonight’s Planet Earth repeats feature the original Attenborough narration, so dive in without reservation. And once you dive in, I expect you won’t resurface for hours. It’s that good.