Be wary of the Sea Devils. Watched as a stand alone it can be very jarring. It's relaly best to watch the Pertwee era in blocks or his entire run, because that way you get pulled into that timeframe and style of that era. Primarily the CSO / bluescreen and the music which often, for the mainstream audience, let the programs down. I'm incredibly tolerant of wobbly sets, tacky monsters and model work, and occasionally bad music, but music in The Sea Devils is appalling even to me. At times the music sounds more like special effects and you can't tell whether laser guns are being fired in a peaceful non-action scene or whether it's just poor experimental electronic. However, the pain can be reduced if you've already been eased in softly to the era's often distracting music, because you grow accustomed to it and start to forget about. But if you watch the Sea Devils as a stand alone story, out of sequence and out of context of that era's dated style, you might find it hard to enjoy what is one of the better outings of the Third Doctor. I know that's longwinded, but I'm something of a classic Who aficionado for 25 years now so anytime you want any input on the series or a particular story, I'll have some essay or two to share.