Chop is the sea condition that ruins more days than big water does, because it is small enough to look harmless in a forecast and rough enough to make the ride miserable. It is short, steep waves raised by local wind, often where that wind is blowing against the current or across confined water.
What makes chop punishing is the spacing rather than the height. The crests come close together, so a boat cannot rise and settle between them and instead drops off one wave straight into the face of the next. That is the slamming, the spray over the bow and the pounding through the hull that turns a two foot forecast into a slow, wet trip and a tired crew.
Chop is a different animal from ocean swell, which is smooth, rolling and widely spaced even when it is large. The two often arrive together, and swell with chop stacked on top of it is far less comfortable than either would be alone. Bays, sounds and the water near inlets are where chop is most common, especially when an outgoing tide meets an onshore breeze.
The practical response is usually speed and angle rather than cancellation. Slowing down keeps the bow from launching, and quartering into the waves rather than taking them square on softens the impacts. Check the wind and wave forecast for your water against the tide before you go, since the worst chop is usually predictable.
