PR was previously handled by marketing director Martin Capel-Smith. He will now look after advertising and trade marketing, with Holloway handling PR and online marketing.
Both report to global V-P of marketing Ben Perrin.
The move effectively splits the firm's PR from marketing as Navman bids to steal market share from rivals such as TomTom, Garmin and Magellan.
Holloway took redundancy from Palm last December following a restructure of his department, and joined Navman earlier this month. One of his first tasks will be to find a European PR manager, following the departure of France-based Ludwig Privats, who has relocated to the US. The role will involve co-ordinating the work of country managers.
Navman's retained UK PR agency is London tech shop Beam, while its five European agencies include Point Virgule in France.
Recently launched sat-nav products iCN720 and iCN750 feature the firm's NavPix software, which provides image-only navigation. Other best-selling products include the iCN 330 portable navigator, and the high-end iCN 550, which directs users to the nearest petrol station.
As well as in-car and personal navigation, the firm makes products for boats and commercial fleets. It also produces outdoor gadgets, such as the R300, which tells runners what distance they have travelled.