Very "meat and potatoes" entertaining, escapist alternate history novel where the residents of Nantucket (and a coast guard training ship that happens to be nearby) are transported back to the bronze age, and start struggling to survive in their new habitat, then expanding.
Taciturn self reliant small business tolerant middle class values get to hold sway while religious nutcases and new age hippy types caricatures are quickly disposed of by taking a strawman versions of their views to logical conclusion.
Despite this, some good swashbuckling fun, and nice and easy to read, with sympathetic main characters (even the main bad guy, Walker, comes across fairly likeable).