A seaplane cannot legally touch down on any stretch of open water in Indonesia — only on a site certified as a water aerodrome under CASR Part 139 Volume III (SKEP/227/VIII/2010, updated by KP 206 Tahun 2021), registered with the Directorate General of Civil Aviation and coordinated with AirNav Indonesia and the Directorate General of Sea Transportation. That paperwork trail, not the aircraft’s floats, is what decides whether a route can actually operate — and it is the first thing worth checking before booking any Bali-departure charter.
Why Does Indonesian Law Treat a Water Landing Site Like an Airport?
A calm bay with no boat traffic is not automatically a legal landing point. Two national laws sit behind every seaplane operation in Indonesia: Undang-Undang No. 1 Tahun 2009 on aviation and Undang-Undang No. 17 Tahun 2008 on shipping, with Peraturan Pemerintah No. 40 Tahun 2012 filling in airport-operation detail. CASR 139.101 treats a water aerodrome the same way it treats a paved runway — as an airport, subject to certification, registration and ongoing compliance rather than an informal nod from a local harbourmaster.
The technical standard, the Manual of Standard CASR Part 139 Volume III, sets minimum physical dimensions, obstacle-limitation surfaces, visual aids and landing procedures for water aerodromes handling seaplanes up to 30 seats — a framework adapted from the US FAA’s AC 150/5395-1 seaplane-base guidance rather than written from scratch. The aircraft-and-operator side of the rulebook, covering pilot ratings and Air Operator Certificate classes, is a separate layer of compliance from the site certification described here.
What Is Happening With Banyuwangi’s Water Aerodrome Right Now?
East Java is the clearest live example of this process in motion. Santai Seaplane (PT Santai Seaplane Aviation), a subsidiary of Hong Kong-based Seaplane Asia Group, announced amphibious operations around Bali and Banyuwangi in a press release dated 25 December 2025, updated in January 2026. The announcement named Banyuwangi Airport (BWX) as a key hub and referenced approved water-landing permits at the Banyuwangi water aerodrome, at Menjangan in North Bali, and at other sites in southern Bali. Commercial services were stated to begin in Q2 2026, pending aircraft delivery and registration — a timeline worth verifying rather than assuming has already passed.
Separately, a LinkedIn post dated 3 January 2026 described a partnership with Bali Kerthi Byomantara to reactivate Letkol Wisnu Airport in North Bali from 2026, using Cessna Grand Caravan amphibious aircraft to link North Bali with Banyuwangi and Denpasar. Our own charter desk tracks that corridor separately, distinguishing what operators have publicly confirmed from what remains feasibility-on-request; ask us for the current status of the Bali-to-Banyuwangi route before assuming a fixed schedule exists.
How Does a Water Aerodrome Actually Get Certified?
Certification runs through several stages before a site can legally receive scheduled or charter seaplane traffic, and each stage produces its own document trail.
| Stage | What It Establishes |
|---|---|
| Site survey | Water depth, tide, current and obstruction data |
| Obstacle-limitation clearance | Height control around approach and departure paths |
| Physical-standard compliance | Touchdown zone size, buoyage and markers under Part 139 Vol III |
| Aeronautical and maritime publication | Site entered on aeronautical charts and maritime safety notices |
| AirNav coordination letter | Formal Letter of Operational Coordination Agreement |
| Register entry | Site added to the national seaplane base register |
A base that has only finished a site survey is not yet a legal landing point, even if test flights have touched down there. The full step-by-step breakdown of who signs off at each stage — DGCA, AirNav Indonesia, the Directorate General of Sea Transportation — sits in our national regulations explainer; this page focuses on what that status means for a route departing Bali.
What Should You Ask Before Booking a Bali-Departure Water Landing?
A route brochure is marketing, not proof of certification. Before treating a resort transfer or scenic stop as confirmed, a booking desk or traveler can reasonably ask for four things.
- Register status: is the specific landing point named in the national seaplane base register, not just described in a press release?
- AOC reference: which operator’s Air Operator Certificate covers the flight, and is it current?
- AirNav coordination reference: has a Letter of Operational Coordination Agreement been signed for that site?
- Alternative plan: what happens — reroute to a certified base, or refund — if sea state or certification status blocks the landing on the day?
Sites still working through survey and clearance stages are best treated as feasibility-on-request: possible, pending, and worth a direct confirmation call rather than a locked-in date. As an independent coordination desk, we ask operators for this documentation before confirming any water-landing leg — the certificate belongs to the licensed operator, not to us.
Which CASR Part Covers Your Charter — 135 or 91?
Most commercial seaplane charters operate under CASR Part 135, the rule set for air-taxi and on-demand charter flown under an Air Operator Certificate (AOC). Some flights — non-revenue positioning legs or owner-flown operations — fall under the lighter Part 91 instead. A published route page for a South Bali–Sumbawa charter, for example, states that flights operate under an Indonesian partner’s AOC 135-067, approved by the Ministry of Transport and DGCA Indonesia. That certificate belongs to the operator, not the booking desk, so it is worth confirming directly before paying a deposit.
What Safety Equipment Is Every Seaplane Required to Carry?
Site certification is only half the picture; the aircraft itself carries separate obligations. CASR Part 91 Amendment 5 requires every seaplane operating in Indonesian waters to carry one life jacket per occupant, sound-signal equipment meeting COLREGs (the international collision-avoidance rules used at sea), an anchor, and a sea anchor where conditions call for one. On the infrastructure side, amphibious handling facilities are engineered to tolerate a surface elevation variation of up to 1.8 inches (0.457 metres) — a tight tolerance that explains why tide and swell data dominate every site survey.
Where a route plan includes a rendezvous with a yacht or phinisi instead of a dock, that meeting point is expected to sit within a coordinated water-aerodrome area rather than an arbitrary anchorage — the same coordination-letter logic that governs fixed bases applies to a moving one. As of 2026, coordination requirements are subject to change as new sites move through the register, so any specific date, permit status or seat count quoted here is worth reconfirming with the operator before travel.