The Sea of Time
It is very telling that the first sea that the Yellow Submarine encounters is the Sea of Time. Here the Beatles first become young before growing very old. This is an interesting way to portray the Time Vortex.
A malfunctioning TARDIS might not shield its occupants from the passage of time. This would limit the time travellers to within their own lifetime and not too far forward or back. A crew with a wide range of ages could get around this limit, with the older time travellers carrying for the young members of the crew when they become children or babies and vice versa.
This would be an amusing complication for an adventure. For a single scenario PCs have to save the day while little children or old men. At the conclusion of the adventure they can fix their TARDIS and return to their original ages.
At the end of this sequence the Yellow Submarine passes its earlier self as it moves backwards in time. If this happened in an adventure would the PCs warn themselves of what was about to happen? Would this disrupt time and create an alternate version of themselves or wipe themselves from existence?
During their travels through the sea of time the Beatles also witness images of old men with pocket watches. It could be interesting if the first Time Lords, such as Rassilon, sign posted dangerous sections of the vortex with images of themselves. What warnings would they hold and would the PCs listen to them?
The Sea of Science
We are shown little of this region, used mostly as a backdrop for ‘Only a Northern Song’. The name itself is perfect for Doctor Who, since science has such an important part in the show.
What we do see is that a section of the Yellow Submarine is duplicated and folded to create a box. Several hundred copies of the Beatles orbit the box, a version of each Beatle placed inside the box, one by one.
Could this realm be home to unseen scientists, duplicating anything one or thing that passed through in order to carry out their experiments? What if they did the same to the PCs TARDIS? What would they do if they knew these scientists not only were trying to duplicate Time Lord technology but had copies of themselves?
The Sea of Monsters
Another very Doctor Who idea. This region appears to be how space is portrayed in Doctor Who, filled with hostile alien life forms. Not only are the multi-coloured dinosaur, living punching bags and lizard cannons likely to be found on strange worlds but the Sea of Monsters could be the ‘dark corners of the universe that bred the most terrible things’ that the 2nd Doctor referred to.
The vacuum monster is a pretty good analogy for the Daleks. It can suck creatures out of existence with its nose, just as the Daleks exterminate other species. The vacuum monster’s actions are therefore a good illustration for what the Daleks will eventually do.
Once the Daleks have wiped out all other life there will only be the universe, which they’ll destroy. Alone they will begin eliminating deviations within themselves, just as the vacuum monster turns on its tail, until they too are gone.
Sea of Nothing
Another blank void, with only one occupant, the Nowhere Man. This would make a good adventure, with the TARDIS landing outside of normal space. What form would their Nowhere Man take?
Non-human Jeremy Hilary Boob Phd is well educated, speaks in prose and easily distracted. He would make a good model for a Time Lord, with a more human appearance, but would make a fascinating alien PC.
His existence raises questions, such as where did he come from? Did he originate in the Sea of Nothing or did he travel there? Did he become trapped or did he isolate himself? Could he have been exiled? Is he some form of Eternal?
Jeremy is painted as a sympathetic figure, with Ringo being touched by his plight. His isolation could be mirrored by a Time Lord who has survived the Time War. Such a character might have escaped the extinction of his race by hiding in the Void, driven almost mad by the isolation. Upon meeting the PCs he might be convinced to return to the universe.
The Nowhere Man the PCs meet might not be so nice. The Sea of Nothing could be a prison and the entity within will do anything to escape. He could play on their sympathy to get on board their vessel, giving him a chance to sabotage it. Those who anger him will find that the Nowhere Man can rewrite their DNA, turning them into living plants, not unlike rose bushes.
This realm of giant heads, with television screens showing their thoughts, could make for a bizarre alien planet. The inhabitants could be telepathic, having mastered the science to make themselves immortal they now just think. Are the images their memories or their dreams?
The Headlands could also represent the Matrix. If Pepperland is Gallifrey it would make sense that this region, so close to their home world, is where the collective minds of deceased Time Lords are kept.
PCs could travel to the Headlands to seek out forbidden secrets, lost memories or to communicate with the departed. There they might become entranced by fantastical images and beings of pure consciousness like Lucy in the sky with diamonds.
Sea of Holes
This vast region of holes is how the Beatles eventually reach Pepperland, since the Yellow Submarine escaped them. The holes are obviously some form of portal. It is even possible to remove a hole, to use later.
The Sea of Holes would make a good nexus point, allowing PCs to travel to other times and planets without a TARDIS. They might know the way home or the quest to find their way back could be part of the adventure or campaign.
It is possible that monsters and aliens on the other side of the holes could claw their way through, travelling to other worlds. Responsible PCs might dedicate themselves to guarding the Sea of Holes and making sure that any intruders are sent back where they belong.
It could also act as an over-arcing threat. The holes could be the first indication that the universe is breaking down. The barriers between space and time are damaged as the holes get bigger and bigger, threating to swallow all of the existence.
This realm is way to portray Gallifrey in a different light. Instead of being a stuffy, dry world of politicians and scientists wondering clinical white corridors it could be a lush garden, a forever lazy Sunday afternoon.
Believing themselves to be safe they spend their time playing, listening to classical music and relaxing. In this version of Pepperland the Time Lords simply don’t have an interest in the outside world, rather than a law that forbids interference.
Rebellious Time Lords are those who want more in life. Pleasure isn’t enough, they want to achieve something. This can give PC Time Lords very different motivations. They aren’t tourists, they aren’t entertained by historical figures. They want to do something.
It would also mean that Gallifrey would have plenty of technology that is long forgotten or discarded. Just as there is a whole fleet of submarines, waiting to be piloted, there could be other wonders in the giant pyramids that dot the landscapes. All of it just waiting for the PCs to discover.
Gallifrey would feel safe because it was so distant from everyone else. In their arrogance they would dismiss news of attack even as their land is invaded. PCs could be put in the position of having to convince others and organise defensive actions.