The pilot was attempting to takeoff on a wet strip, which sloped markedly down from the centre towards each end. To minimise the effect of a slight tailwind, and to avoid an obstruction at the end of the strip, the pilot planned to angle the ground run. Takeoff was commenced from the left side of the strip, but when the aircraft had reached the top of the hump in the strip, the pilot realised that he had angled the run excessively and was now outside the markers on the right side. The aircraft subsequently collided with scrub and trees. The strip markers were difficult to see, and had compounded the pilot's difficulty in accurately assessing the angle at which he planned to carry out the takeoff. At the point where the pilot realised the aircraft was running off the side of the strip there was insufficient distance remaining to either abandon or safely continue the takeoff attempt.