Open-Trip, 20–28 m
- 6–10 berths, bunk or twin, shared heads acceptable.
- Panrita lopi judgement, minimal class; 250–450 hp combined.
- Turnkey USD 120k–400k (estimate).
Cabin count, dive deck, engine sizing and structural standards — each phinisi design decision translated into cost and charter yield, with every bracket flagged as an estimate.
The panrita lopi carries the design in his head — no drawings, no stability calculations. Many such hulls are sound, but none leave a record an insurer or surveyor can audit. At specification stage, every choice is a cost line.
Once major structural choices are built in, they are not revisited. These three are made before the keel is laid — or paid for later.
Fix the charter market, price point and waters first. A Komodo mid-range dive boat and a luxury Raja Ampat week-charter look different; conflating them buys an expensive compromise.
Scantlings reviewed to GL, Bureau Veritas or BKI produce the stability booklet a passenger certificate needs — and keep insurance off the top of the 1.5–4% premium range.
Ulin for keel and frames, bitti for curved planking, teak for decks — vertical-grain, 25 mm minimum. If a quote looks low, ask for the species list and provenance certificates.
More cabins is not more revenue. Below USD 400 per person per night, berth count dominates; above it, ensuite ratio and privacy do. Partitioning is set at planking.
On a dive liveaboard the dive deck is the product. Engines, rig and power are where under-specified builds lose charters.
A lines plan agreed with the panrita lopi, a stability calculation for your load cases, fastener specs that prevent a USD 100,000 bolt surprise, and a document trail for BKI, insurers and resale.
Short answers. Cost and power figures are industry-observed estimates unless marked.
For a budget open-trip boat under local standards, often not. For Western charter markets, international insurance, BKI class or a passenger certificate that needs a stability booklet, yes — the architect is how those documents get produced.
It depends on price point. Under USD 400 per person per night, maximise berths with five to eight cabins and shared facilities. At USD 600 and above, four to five large ensuite cabins command the premium rate.
Kasten puts yacht-spec phinisi at around 850 hp total, against 250–350 hp for cargo hulls. Two mains of roughly 250–425 hp each plus two independent generators is common at 30–38 m. Have an independent engineer model the power budget.
Solar for low anchorage loads is practical and increasingly common. Full hybrid systems face battery weight against the stability curve, wet wooden-hull electrics and few qualified technicians. Ask an architect, not a panel supplier, for a lifecycle cost model.
It is a structural load path — mast partners, chainplates, keel reinforcement under the mast step — that must be designed in. Sail photos drive bookings. And a neglected masthead fitting is an expensive failure at sea.
Plan six to twelve months from hull launch to commercial operations for a properly documented new build. Stability review, BKI survey, passenger certificate and operating licence do not move at the yard's pace.