A morning boat trip out to Pelican Point at the tip of the sand spit is the classic Walvis Bay activity. Several operators (Mola Mola, Catamaran Charters, Eco Marine Kayak Tours) run almost-identical half-day catamaran tours that leave the marina around 9 am, cruise across the lagoon, visit the Cape fur seal colony at Pelican Point (around 60,000 seals), often pick up dolphins playing in the bow wave, and on a lucky day spot humpback or southern right whales between August and October.
The tours invariably include a brief stop at an oyster farm where you can taste fresh oysters straight from the water, followed by a small champagne breakfast on board. A pelican usually lands on the deck for theatrical effect (the captains feed them). Cost is around N$700–900 per person; book a day in advance through your accommodation. Sea sickness is rare in the sheltered lagoon but the wind can be cold.