100A service (twin-50A or single 100A) is required for yachts 50 ft+ with dual A/C, electric galleys, and shore-charging requirements. Not every marina has the pedestal infrastructure — confirm before signing a slip contract.
Twin-50A pedestals provide 100A total at 240V — enough for two large A/C compressors, a water heater, electric range, and battery charger simultaneously. Critical for any liveaboard yacht over 45 ft.
Single-leg 100A service at 240V is rarer and limited to luxury and megayacht facilities. Pricing is almost always metered, $0.25–$0.50/kWh.
Reading past the brochure
Brochure copy makes most marinas sound interchangeable. Marinas with 100A Shore Power are usually differentiated by something specific: marinas supporting twin-50a and 100a service for large yachts and liveaboards. That detail is what separates a marina that fits your boat from one that just happens to have an open slip.
Before judging fit, write down your boat's LOA (including platforms and pulpits), beam, draft at mean low water, power requirement, and how often you'll actually be aboard. Then compare against the marina's reality, not its photos.
What the marina is checking on its end
Behind the counter, the dockmaster is matching your numbers to a specific finger: slip length, beam clearance, water depth at low tide, fairway width on the approach, the right power pedestal, and whether neighboring boats are compatible.
If any of those numbers don't work, a careful marina will offer a different slip rather than crowd you in. Push for that conversation — being told "we'll make it work" is sometimes how boats end up wedged into the wrong berth.
Pricing reality check
Treat $150 – $400+ / month (flat) or $0.25 – $0.50 / kwh as the planning range and ask any marina in this category for three numbers in writing: base rent for the slip they would actually assign you, average monthly electric for a boat your size, and the all-in monthly total including tax. If the dockmaster won't break it out that way, assume the gap between the brochure rate and your real bill will be at least 15–25%.
The amenity list, decoded
Expect a typical amenity stack of twin 50a pedestals, metered billing, gfci protection, smart pedestals. Read it less as a feature list and more as a signal of how the marina is staffed: a marina that lists 24/7 dockmaster, on-site mechanic, and fuel is operating very differently from one that lists pool, bar, and concierge. Pick the operating model that matches how you actually use the boat.
Pros and cons
Pros
- • Matches a clear way of using a boat, so the slip search gets shorter
- • Easier to compare apples-to-apples against similar marinas nearby
- • Amenities, rules, and dockmaster expectations are predictable
- • Pricing patterns are well understood, so quotes are easier to vet
Cons
- • Availability can be tight in season or in popular harbors
- • Headline rates often leave out power, tax, and resort fees
- • House rules vary widely from one operator to the next
- • The best slips often require deposits or sitting on a waitlist
Red flags during the reservation call
Be cautious if the marina won't quote an all-in number, can't tell you the exact slip you'll be assigned, dismisses your insurance questions, or hedges on the storm plan. None of those are killer issues by themselves, but together they usually predict friction later.
On the other hand, a dockmaster who asks for your draft, fuel preference, and arrival ETA before you ask them is usually running a marina worth the money — even when the per-foot rate is higher than the harbor next door.
Best for
- • Yachts 50 ft+
- • Liveaboards with electric galleys
- • Catamarans with twin A/C