First, let it be said that the National Maritime Museum (NMM) has an active relationship with contemporary art that is worthy of praise.

On entering the building, the gentle wash of waves breaking over shingle - a 1999 sound installation from Bill Fontana - greets the visitor. Second, Weiner's Inherent in the Rhumb Line, the latest in the NMM's New Visions series, is a show finely tuned to the interests of its venue.

If rhumb lines are fictional lines, then so too are the longitudinal lines that delineate time. As Greenwich sits on zero degrees longitude, it is the perfect place to think about time and distance.

Weiner has worked across several formats - video, music and graphic art. It is the last category for which he is best known, in particular his huge 'word' works, in which texts are writ large in public spaces - part installation, part sculpture, part poetry.

Weiner, now in his 70s, came of age - like Ed Ruscha, Jenny Holzer, Barbara Kruger and even Warhol - in a period when fine art drew on the directness of commercial art to create something new and more knowing.

What you first see on entering the elegant space devoted to Weiner is a series of poster-sized sketches, each lettered in Weiner's trademark capitals. 'KEEPING WITHIN THE LINE' and 'RHUMB IS AS RHUMB DOES' are phrases that reappear in the subsequent rooms, as do 'SAIL ON' and '&'.

These motifs, sometimes on paper, other times mounted on white walls in big plastic lettering, are as much phrases and typographical marks as they are shapes. Communication begins with abstractions here.

Weiner edges both his letters and typographical shapes with black borders, bestowing a pop-art boldness on the vivid colours and movements that arcs, arrows and dashes imply.

One room has work that is wonderful in its simplicity: red letters edged with blue read 'CLEAVED THROUGH THE NEXT WAVE'. They are bisected with black lines, then 'OVER THE BOUNDING MAIN' and 'KEPT WITHIN THE LINE'. In another room, a wall is covered with the lyrics of a romantic song.

This is work that is about the objects' relationships with each other and the space between them. Weiner has used voyage as a metaphor for this in the show, but he could just as easily chance on a different system of expression for another.

After seeing Weiner's shapes, it is a strange experience to stray into the NMM's Nelson exhibition to play with an interactive model of the Battle of Trafalgar, where ships are represented by brightly coloured silhouettes.

As HMS Victory and Temeraire manoeuvre into position, it is possible to see in them the movement implied by Weiner's own boldly outlined shapes - a world where stasis can be only a theoretical point.

Louise Gray is a freelance arts journalist

Inherent in the Rhumb Line is at the National Maritime Museum, London, until 9 December, www.nmm.ac.uk