A ship's lookout is required by maritime law, not just for the simple amusement of the permanent crew as popularly thought.
Lookout is performed with a buddy. The primary purpose as a lookout is to make sure your lookout buddy doesn't go overboard whilst peeing from the side.
Be sure to arrive to relieve the lookout a few minutes early, before your buddy, not for any courtesy, but to get your preferred side of the ship. Ideally where the sun's warmth shines and a rogue wet wave is less likely.
The hard wooden seats first appear to be the logical place to park your bottom however there are better options. The large coiled anchor ropes in the centre of the deck offer a soft padding for your butt or back. Sitting atop is an attractive choice, just beware not to suddenly fall backwards. Even better is to sit on the deck and slouch back into the pillowy fibers. You won't be able to see the horizon all the time this low, so feel free to close your eyes now and then. If anyone questions this, explain to them you are merely training your night vision - even during the day.
It is a splendid opportunity to multi-task; sunbake, listen to music, discuss food fantasies, stretch, watch other people work and avoid the nuisance of sailing handling.
In Antarctica, it is also an opportunity to freeze to death. Wear extra layers, the foredeck is often the coldest part of the ship, you won't be moving much, and more layers means more pockets to hide tasty snacks.
If the weather is foul, the lookout will be moved to the poop deck where you'll have a front row view to watch your crew mates get slugged by sudden monster waves as they scoot awkwardly across the main deck. Be sure to cheer wildly as they're sodden and drenched cold.
Finally, definitely buzz the officer of the watch in the wheel house often. Radar is just voodoo and shouldn't be relied upon.