Which business line is most likely to require a proposal form within the London Market?

Yacht insurance is most likely to require a proposal form within the London Market due to the specific nature and complexity associated with insuring marine vessels. Yacht insurance policies typically involve detailed assessments of the vessel's characteristics, including its value, type, usage, and any other factors that might influence risk.

Proposal forms are often utilized in these scenarios to gather comprehensive information about the yacht, the owner’s experience, intended use (such as leisure or racing), and information regarding security measures. This detailed information is crucial for underwriters to evaluate the risk accurately and provide an appropriate premium.

In contrast, while property, motor, and health insurance may also use proposal forms, they might not require as much detailed information or customization typical of yacht insurance. Property and motor insurance tend to have more standardized underwriting criteria, and health insurance may rely more on questionnaires or medical history rather than an in-depth proposal form like that used in yacht insurance assessments.