The contract, worth around €27m, will keep the yard's slipways busy until 2029 and replace the diesel boats that cross between Old Quay and the Saltings.
Every weekday at twenty past seven, a dozen or more passengers gather on the upper deck of the Saltings ferry to talk about a novel. The crossing takes 35 minutes; the club has lasted three years.
Forecasters expect a lively weekend, with squally showers and gusts of up to 65 mph on exposed parts of the coast, while the Asher Valley and Greyling Hills should see longer dry spells.
For the first time in its history, the public can climb the 117 steps of the Fenwick Point lighthouse, take a guided tour of the lamp room and have lunch in the old keeper's cottage.