Taxi
Official SLASPA-licensed rank inside each terminal; posted fares; ~US$25 round-trip to Pigeon Island
The Saint Lucia Air and Sea Ports Authority (SLASPA) operates the licensed taxi rank inside both cruise terminals. Drivers carry blue-and-yellow TX-prefix licence plates and a SLASPA cruise-rank badge. Fares are posted at the rank: US$25 round-trip to Pigeon Island / Rodney Bay (with 3-hour wait), US$30 round-trip to Marigot Bay, US$160–200 round-trip to Soufrière (full-day, 8 hours, up to 4 passengers), US$15 one-way between Pointe Seraphine and La Place Carenage by road. Confirm the fare and the wait time in writing before getting in. There is no Uber, Lyft, or Bolt in Saint Lucia. Public minibuses (route 1A is the Castries–Rodney Bay run, EC$2.50 / about US$1) are the local option but run set routes and are cramped for cruise passengers. The water-taxi between the two terminals and downtown is EC$5 / US$2 each way.
Currency
Eastern Caribbean dollar (EC$/XCD), pegged at EC$2.70 = US$1; USD accepted everywhere on the cruise corridor
The Eastern Caribbean dollar (EC$, currency code XCD) is fixed at 2.70:1 with the US dollar by the Eastern Caribbean Central Bank and has been since 1976. USD is accepted at every cruise-corridor business — the duty-free terminals, Sulphur Springs, Pigeon Island, Royalton and Bay Gardens, the licensed taxi rank, the water-taxi, the catamaran operators. Tourist-facing businesses sometimes use a 2.5:1 or 2.6:1 rate in their favour rather than the official 2.70; small difference, not worth fighting. Change is usually given in EC$ — that's normal, take it for the small things. Cards work at all formal venues; cash matters for taxis, the Castries Market (cash-only, EC$ or US$), small beach vendors, and tipping. There is no need to exchange currency. ATMs at Pointe Seraphine dispense EC$ only. Restaurants typically include a 10% service charge plus 10% VAT — check before adding a tip.
Day trip
Pigeon Island + Rodney Bay (4 hrs, the easy win) or Soufrière + Pitons (8 hrs, the full island)
The two real choices on a Castries port day are north or south. North is Pigeon Island National Landmark and Rodney Bay — a 4-hour round trip that fits any port call: 25 minutes' drive each way, US$10 entry to Pigeon Island, the Fort Rodney hike (30 minutes uphill, panoramic views of Rodney Bay and on clear days Martinique 40 km north), then a swim at Reduit Beach. Total cost roughly US$50 per person all-in. South is the Soufrière full-day at 7–8 hours: Sulphur Springs (the drive-in volcano, US$10 entry), the Pitons photo stop or a boat to Anse Chastanet, and lunch in Soufrière. The catamaran from Pointe Seraphine that sails to the Pitons (5–6 hours, US$110–140) is the road-avoiding upgrade. Mid-island options: Marigot Bay (30 minutes south, the harbour where Doctor Dolittle was filmed in 1967, US$30 round-trip taxi, 3-hour outing), or a rainforest zipline at Treetop Adventure Park (2 hours, US$95 ship tour).
Dock
Pointe Seraphine (north, 2 berths) or La Place Carenage (south, 1 berth); alongside, no tendering
Castries Harbour has two cruise terminals operated by the Saint Lucia Air and Sea Ports Authority (SLASPA), on opposite sides of the harbour. Pointe Seraphine on the north side has two alongside berths and can take two large ships (up to roughly 360m / Quantum-class) simultaneously. La Place Carenage on the south side has one berth and is used as the overflow on three-ship days or for smaller ships. Both terminals are alongside, deep-water berths in a sheltered harbour — tendering is rare and only happens on four-ship days when smaller ships anchor off Vigie Beach. Pointe Seraphine has the larger duty-free complex (about 25 shops), restrooms, free Wi-Fi, the official tourism desk, the licensed taxi rank, and the water-taxi pier to downtown. La Place Carenage has its own smaller duty-free mall (about 12 shops), restrooms, taxi rank, and a 2-minute walk to the Castries Market. Confirm which terminal your ship uses on the daily — it changes call to call.
Dive sites
Anse Chastanet Marine Reserve (south, 90 min away); Anse Cochon (mid-coast, 45 min) for shorter calls
Saint Lucia's serious diving is on the southwest coast inside the Pitons Marine Management Area. Anse Chastanet Reef (3–40m, the wall drops straight from a black-sand beach into healthy hard coral and sea fans), Superman's Flight (the underwater wall on the side of Petit Piton, 6–40m, drift dive), and Coral Gardens (8–20m, easy reef) are the headline sites. Scuba St Lucia at Anse Chastanet is the operator with the most cruise-day pickups; from Castries it's a 90-minute coach transfer or a 25-minute helicopter, so a single-tank cruise dive runs US$160–200 with gear including transport. Anse Cochon (mid-coast, 45 minutes from Castries) is the closer alternative — a black-sand bay with two shipwrecks (the Lesleen M tug at 18m, the Daini Koyomaru cargo ship at 21m) and a US$110–140 single-tank cruise dive. Visibility 18–25m year-round.
Beach clubs
Reduit Beach (Rodney Bay) day passes US$50–90 at Royalton or Bay Gardens; Anse Chastanet only viable on long calls
Reduit Beach at Rodney Bay (25 minutes north by taxi) is the standard cruise-day beach. The Royalton Saint Lucia all-inclusive day pass is roughly US$90 per adult and includes food, drinks, beach chair, umbrella, and pool access; the Bay Gardens Beach Resort day pass is US$50–60 with a US$30 food-and-drink credit. Both are bookable on the day at reception, subject to availability — book ahead on heavy cruise days. The free public access to Reduit Beach is immediately adjacent and beach vendors rent chair-and-umbrella sets for US$20–25. Anse Chastanet near Soufrière is the iconic black-sand beach with the Pitons backdrop and the on-site dive shop is one of the best in the Caribbean, but at 90 minutes each way it's only viable on a 9+ hour call or paired with a Soufrière day. Vigie Beach is the walking-distance option from Pointe Seraphine but rarely the best use of port time.