A perceived limitation of the current Web is that it is comprised of static links with no connection to any underlying domain knowledge. The Semantic Web is seen as a potential solution to this problem by delivering semantically related information to users dynamically. However, the benefit to users is rarely questioned and there have been few real-world user evaluations of semantic systems. In this paper we present a user-centred evaluation of three Semantic Web Browsers (SWB) that have been extended as part of the Sealife project. The results presented are based on analysis of the server logs from each application in relation to time taken to perform pre-defined tasks along with the amount of semantic activity carried out. It was found th...