Just had our first race of season and I was pretty happy with my time until a buddy who watched the race from a rubber duck said the paddler who was next infront of me was 200 meters infront of me at the first turn (2km mark) and still only 200 meters in front at the finish (10km).

He said to me "Why did you let him get in front of you? You both paddle at the same speed".
I can see what he means now. I tryed to stay with that guy at the start. I was with him for about 200 meters before he started to get away from me and my top speed dropped.

My max speed seems to be equal to him on the start, I just cant hold it for long enough. Is there any particular training to improve this aspect of my race or do I just keep working on my interval session and speed session each week and try harder next time?

Thanks for your thoughts.

Although the problem may appear to be the segment where he got ahead of you... i.e., speed... there are many strategies for endurance races. Both tortoises and hares can win if they maximize their strengths and reduce weaknesses. Red twitch types (tortoises) may do better trying to negative split a long race; i.e., maintaining a high but continuously building rate of speed, never really sprinting and hoping to judge it correctly so that they are spent at the end, but not before the end. White twitch types (hares), on the other hand, may do better using their speed to get out fast, not allow others to pass them, and try to hold on, hoping to have enough left in the tank to use their speed again at the end to grab another place or two. Training strategy should focus mostly on your strengths, but not neglect weaknesses, which depends on which type you are as well. If red twitch, then long intervals, trying to increase your ability to hammer at 80% for longer. If white twitch, then shorter, faster intervals, trying to increase the speed and the number of these you can do with little rest between. Of course, one should do all types of training, but tailor your training and your race strategy to your muscle type and psychological type. Maybe you are the type that needs to be able to build steadily through the race... let that fellow get away a little at first if he insists on sprinting ahead, but through training, ramp up your 80% speed to the point you'll eventually run him down, pass him, and wear him out trying to hang with you... the converse if you're the other type.

You can save 10-15% energy by "surfing" on the wave generate from the kayak next to you (when the kayak is a little in front of you). Like the V-shape you can see when birds are flying together.

So the tactic for most long distance races, is to paddle as fast as possible for the first 1-2 km (to loose the slower paddlers) and then group up and work together to reach the finish as fast a possible. It's a sprint in the end to win.

When waves get bigger the gain of staying together become less. Downwind waves becomes more efficient.

It takes time and effort to learn howto stay in the "sweet" spot when surfing on the kayak generated wave.