Generally Personal Effects or Personal Property is defined by Underwriters as any property you would remove from the vessel if the boat was sold. A good example of this is foul weather gear or fishing gear.
Most of the time this type of property is personal in nature, sized to fit or custom built, and you would keep it for your next boat.
Equipment such as engines, electronics, safety gear and the like usually stays with the boat when sold and is not considered to be Personal Effects or Personal Property.
This is an important issue since many times clients over or under insure Personal Effects or Personal Property and either pay too much or are not properly protected.