I agree that one option is as wuff stated. Another option, that is possibly too expensive for you, but that would look really good, is the use of lattice. If you purchase lattice that has the edging to it and erect it so that the height remains the same as the fence on the RHS, this could work. I would not recommend painting it as this would lead to regular maintenance. There are various sorts of lattice that you could consider. Don't put a climber on it unless you want the maintenance. If you wanted this extra care, you could espalier a climber like Star jasmine which is evergreen, or Boston Ivy which is deciduous.

Breaking up the great solid block of colour a little bit helps to hide it. Next is the choice of what to plant. I'm leaning towards: ficus pumila, climbing fig, which can be pruned to hug the fence tightly, Himalyan blue bamboo, (but might sprout on other side of fence as well, so should have a 60cm deep root guard or be planted in pots) or waterhousia floribunda, weeping lilypilly, which can be pruned to a narrow, non-climbable hedge but 30cm might be about as narrow as possible. I'm just a bit scared the bamboo will move into the neighbours yard too...You also have to be careful to not plant anything with massive roots that could eventually crack your pool, and it has to be tough enough to cope with a bit of chlorine... Then, put in a dip line so you don't have to water such a narrow spot. Good luck, and let us know what you decide.

Nice pool, but a shame that your neighbours can see you through the fence, and therefore, you get no privacy. If you were wanting privacy of some kind, bamboo, tikka plant or even lovely conifers will look quite nice, also as a backdrop to your pool area. I would also place a beautiful urn or two strategically near the pool, to add character and colour. I would finally add an order of large stones for good effect.

Here is the trim colour - to help others out. and in use...