Most of the population and businesses in Malta are based on the east side of the island around Valletta.
There are several marinas around here and plenty of businesses in the area, including quite a few independent restaurants/bars. Lots of people commute into Valletta by getting the regular ferry service which runs across the water on both sides to Sliema and Birgu respectively.
On the South coast of the island Marsaxlokk and Marsascala both have quite a few restaurants albeit no real marinas as such (mostly small local boats for fishing etc.). Marsaxlokk does get a lot of day-trip tourists, particularly at the weekends.
Valletta and surrounds is a busy area. The traffic can be bad, so getting the ferry service onto Valletta is usually easiest. A lot of the roads on Malta are in poor condition, your sat-nav may well send you down some dubious looking tracks!
The local beer (Cisk) is very good, and the local pastizzi are also excellent and very cheap (30c in most places).