About 8 miles downstream—which means seaward, to the east—from central London, Greenwich is a small borough that looms large across the world. Once the seat of British naval power, it is not only home to the Old Royal Observatory, which measures time for our entire planet, but also the Greenwich Meridian, which divides the world into two—you can stand astride it with one foot in either hemisphere. Bear in mind that the journey to Greenwich is an event in itself. In a rush, you can take the driverless DLR train—but many opt for arriving by boat along the Thames.

Days at sea are the perfect opportunity to relax, unwind and catch up with what you’ve been meaning to do. So whether that is whale watching from the Observatory Lounge, writing home to your loved ones or simply topping up your tan by the pool, these blue sea days are the perfect balance to busy days spent exploring shore side.

Nestled in the mouth of a wooded estuary, Fowey (pronounced Foy) is still very much a working china-clay port as well as a focal point for the sailing fraternity. Increasingly, it's also a favored home of the rich and famous. Good and varied dining and lodging options abound; these are most in demand during Regatta Week in mid- to late August and the annual Fowey Festival of Words and Music in mid-May. The Bodinnick and Polruan ferries take cars as well as foot passengers across the river for the coast road on to Looe.

St Mary’s is the Isle of Scilly’s largest island with a population of 1800 residents and an area of 6.58 square Kilometres; this is the gateway to the rest of the magnificent islands. Hugh town -a beautiful Old town with its own beach, nature reserve and church is the main attractions of St Mary’s, with tiny streets brimming with shops to pick up the perfect souvenir. St Mary’s is a hidden gem, with long stretches of white sandy beaches and a breath-taking untouched landscape. The coastline holds many archaeological sites along with miles of splendid walks along the coastal and country paths.

Ask any Dubliner what's happening and you may hear echoes of one of W. B. Yeats's most-quoted lines: "All changed, changed utterly." No matter that the decade-long "Celtic Tiger" boom era has been quickly followed by the Great Recession—for visitors Dublin remains one of Western Europe's most popular and delightful urban destinations. Whether or not you're out to enjoy the old or new Dublin, you'll find it a colossally entertaining city, all the more astonishing considering its intimate size.

Before English and Scottish settlers arrived in the 1600s, Belfast was a tiny village called Béal Feirste ("sandbank ford") belonging to Ulster's ancient O'Neill clan. With the advent of the Plantation period (when settlers arrived in the 1600s), Sir Arthur Chichester, from Devon in southwestern England, received the city from the English Crown, and his son was made Earl of Donegall. Huguenots fleeing persecution from France settled near here, bringing their valuable linen-work skills.

Trendy stores, a booming cultural life, fascinating architecture, and stylish restaurants reinforce Glasgow's claim to being Scotland's most exciting city. After decades of decline, it has experienced an urban renaissance uniquely its own. The city’s grand architecture reflects a prosperous past built on trade and shipbuilding. Today buildings by Charles Rennie Mackintosh hold pride of place along with the Zaha Hadid–designed Riverside Museum.Glasgow (the "dear green place," as it was known) was founded some 1,500 years ago.

Oban, "little bay" in Gaelic, today has a resident population of 8,500 and is the unofficial capital of the West Highlands - the "Gateway to the Isles." The panoramic views of the mountains, lochs and islands which have captivated artists, authors, composers, and poets for centuries are as striking now as they were when Dunollie Castle, a ruined keep which has stood sentinel over the narrow entrance to the sheltered bay for around six hundred years, was the northern outpost of the Dalriadic Scots.

Once a northern defense post against Irish raiders, Holyhead later became best known as a ferry port for Ireland. The dockside bustle is not matched by the town, however, which maintains just a small population. Nonetheless, thousands of years of settlement have given Holyhead rich historical ruins to explore, with more in the surrounding hiking friendly landscape.

The bustle of this resort town's fishing harbor, yachting center, and commercial port only adds to its charm. In the 18th century Falmouth was the main mail-boat port for North America, and in Flushing, a village across the inlet, you can see the slate-covered houses built by prosperous mail-boat captains. A ferry service now links the two towns. On Custom House Quay, off Arwenack Street, is the King's Pipe, an oven in which seized contraband was burned.

Spend your last evening in London.

Disembark this morning after breakfast.