A kayak’s weight limit isn’t a precise tipping point. If you’re a pound over the maximum weight limit, that doesn’t mean your kayak will sink like a stone. How well your kayak performs when heavily loaded will depend on a number of factors including the distribution of weight, water conditions, and your experience as a kayaker.
There’s no industry standard to determine a kayak’s weight limit. Different manufacturers have different approaches to setting weight capacity. Some allow for a generous margin of error, others will treat the term “maximum” quite literally.
If you’re looking to test your kayak’s maximum weight capacity, I’d suggest doing it in a safe environment where it doesn’t matter if you get wet!