What matters in OC 1 race performance ?
All things matter.The typical "it's the engine and not the boat" may sound good to some, but it is not convincing.
PaddlerMotivation, incentives, access to good training waters, finances, family status. Smaller and lighter paddlers do well in long distance and agitated conditions, heavier and taller paddlers can dominate in shorter sprint events.
WeightWeight, boat and paddler combined, is the single most important factor. It determines how deep the boat sits in the water and thus the drag.
ExperienceThe more, the better. This is also true for race tactics, conditioning etc.. Good nutrition can be mentioned here, too.
TechniqueThere are many different styles of paddling, long/short, flat/open ocean, etc. all demand different abilities. Your technique will adapt to the conditions that you paddle in most frequently.
ConditioningLet's assume that everyone, who wants to race, is well conditioned.
Local water knowledgeVery important. If you know the currents and wave/tide behavior, you will be able to judge your performance during the race and can adapt accordingly - a huge advantage.
EquipmentCanoeDifferent canoes for different conditions.
Waterline length, beam. draft, rocker, design volume, entry, shape - they all matter and determine the behavior of a boat.
They are definitely not 'all the same'.
PaddlePaddle length and paddle width definitely matter. A wide blade may be good for up to an hour, a narrower blade may be more efficient overall in a long distance race.
Whitewater paddlers like scooped blades, North American paddlers like bent shafts, Olympic paddlers usually have straight shafts etc., again a huge variety.
Race courseA good surfer may not do as well in the flats, a good flat water paddler may not feel as comfortable in the open ocean etc..
ConditionsWind, waves, currents - we all like some conditions better than others.