Crew transfer vessel simulator — the push-on at a wind turbine, in the browser

A technician steps from a moving bow onto a ladder bolted to a steel tube in the open sea. Whether that step is safe depends on the person at the jets: the speed of the touch, how square the fender sits on the landing, and how much thrust holds her there while the sea lifts and drops her bow. Those skills are usually learnt on the real boat or in a full-mission simulator room. Our CTV puts them in a browser tab, at a real wind farm with 80 turbines where they stand. You can drive her now in the browser, on your phone too.

The boat

The CTV is a 26.0 m aluminium catamaran, 10.0 m beam, 1.5 m draught, about 60 t — the working boat of the wind farm.

• Two waterjets of about 1 050 kW: 25.8 kn flat out; astern on the buckets about 60 %.
• The jets steer ±30° and pivot her: Q / E put one jet ahead and one astern and she turns on the spot.
• Stopped in 20 kn of beam wind she drifts at about 1.3 kn — remember it when you set up on the landing's line.
• Her bow carries a big rubber push-on fender, always out; at an exercise's start her side fenders go out too.

The 3-D view shows her as she is: two hulls under a cross deck, the orange wheelhouse amidships forward, the raised bow transfer platform with its rails, the push-on fender running flat across both bows, and the jets' nozzles turning with the helm. The turbine ahead of you is built in three dimensions too — the yellow tower from the water to the access platform at 17 m, the jacket legs with the landing braced to one of them, the rotor turning at about 13 rpm into the wind, the nacelle's red light at night.

What you learn on her

Every skill below is a control, a gauge or a judged exercise on the screen. ↑ ↓ work both jets, ← → steer, Q / E pivot. Near a turbine her panel shows the PUSH-ON gauge.

• The approach — the recommended track (┄ GUIDE, Shift+G) runs onto the landing's normal 120 m out, HEAD TO SEA, then straight in: SLOW 3 kn at 80 m, DEAD SLOW at 25 m. A faint dashed line on the water; it never changes your score.
• The touch — come in square and centred on the landing's ladder at 0.5 kn or less. Between 0.5 and 1.0 kn costs 20 points; over 1.0 kn is HARD LANDING and the exercise fails. Pushing hard before the fender is on drives her onto the landing.
• ON THE LANDING — the gauge shows it when her bow fender is in contact with the landing's two tubes (Ø 0.45 m, 1.5 m apart), as the physics has it, not as a tick box.
• Holding on with thrust — push, and the rubber GRIPS the tubes while your thrust beats the sea heaving her bow up and down them. Too little for the sea and she SLIPS: her bow jumps and twists. In a moderate sea about a third of her thrust holds; as the sea builds you need more. The gauge reads GRIP, 1.0 the edge.
• Where she touched is where she stays — the fender holds her bow against sliding along the tubes. Off the ladder (more than 0.9 m): ease the push and steer across, or back off and come in again.
• The transfer — square within 10°, centred within 0.9 m and gripping for 5 s, and a technician steps over (6 s). A slip then stops him. Two technicians per run, then ASTERN 20 m off the landing (CLEAR).
• Sea state limits — in a 0.8 m sea about a third of her thrust holds every wave; at 1.4 m you need well over half; beyond about 1.8 m no push holds every wave. You learn the limit by meeting it.
• The 500 m zone — one covers the whole of BALTIC 2, the water between the turbines included. Free Mode says NO ENTRY WITHOUT THE INSTALLATION'S PERMISSION; only vessels working the farm go in.

Her two judged exercises are in ⛽ OFFSHORE (beside SHARED SEA) → OFFSHORE PRACTICE. BOAT LANDING — PUSH ON puts her 380 m out on the line of turbine B2-H8's landing on the farm's south edge, a jacket whose landing faces 168°: 12 kn of wind on her bow, Hs 0.8 m, 0.4 kn of current setting off the turbine; −10 a slip, more than four fail. PUSH ON IN A RISING SEA is the same landing at Hs 1.4 m, 20 kn and 0.6 kn, three slips allowed. Each scores out of 100 with up to three stars (★★★ from 90, ★★ from 75); your best is kept in your browser. ⚓ DOCK opens the view from above with the landing, its line and the exercise's boxes. FREE PRACTICE puts the CTV in BALTIC 2 in the real weather with no judge — every turbine has its landing, two on a monopile, one on a jacket.

Both exercises have ▶ DEMO: a demo skipper drives her on the real controls — the guide's line, the touch at a walking pace, PUSH ON for a grip well over the sea's heave, astern off — each control lit with an orange ring as he uses it, the DEMO bar saying the order and why. Touch a control to take over, or watch to the end and press ▶ YOUR TURN.

The sea is real

Free Mode starts in the Gulf of Riga, in full detail, and the whole Baltic is yours: with the simulator subscription the coasts and harbours come in detail from Luleå to Skagen and Kiel, loaded as she goes, and AREA opens a picker of 107 real harbours to start from. The BALTIC 2 wind farm stands north of Rügen with its 80 turbines placed after OpenStreetMap, 39 on monopiles and 41 on jackets, marked as a real farm is: the corner turbines flash yellow every 5 s, the other edge turbines Fl(3) Y 10 s, every nacelle a red light; the nearest turbine's ID board shows within 400 m; the turbines paint strong echoes on the radar. Farther east stand the platforms BALTIC BETA, PG-1 and the oil platform, and in the Gulf itself TRAINING PLATFORM GR-1 — a training object, not a real structure.

The weather is today's: the wind is MET Norway's real forecast where you are, with the cloud, rain, snow and fog it brings; the sun, moon and stars stand where they really stand. The sea builds with the wind, and it is the sea that works against your grip on the landing. CURRENT shows the water moving — offshore about 2.5 % of the wind's speed, 20° to its right. Round you is COLREG traffic AI that gives way and stands on, on a radar PPI with AIS overlaid and an OpenSeaMap chart.

Shared sea — other real people on the water

Logged in, SHARED SEA is on by default — one live sea for everyone at ×1 — and you can switch it off. The boats you meet are other skippers' boats, driven by real people at that moment, and the Rules are applied for real by both of you. A CTV at 25 kn closes with a yacht very quickly: you learn to show your intentions early. A PRACTICE WIND of your own is yours only; the others keep the real wind and see PRACTICE WIND beside your name.

Classroom and the scenario builder — for schools, clubs and instructors

An instructor builds an exercise in ✎ SCENARIO BUILDER: the place (any harbour of the Gulf or the Baltic, or any point on the chart), the OWN VESSEL from the VESSEL list, the CTV among them, TIME & WEATHER (any clock time on any date, wind with gusts and veering, visibility down to thick fog, the sea state), other vessels with their types and routes, AREAS and TRIGGERS. ⇗ MAKE A LINK packs the whole scenario into the link itself; whoever opens it is ready to ▶ RUN.

🎓 CLASSROOM puts a class on one private sea. TEACH is for the instructor: a name, what the class sails — FREE SAILING, a SCENARIO, a DOCKING LESSON or a DRILL, offshore among them — and OPEN THE CLASS gives a code and a link. Up to 30 students join from any browser. The INSTRUCTOR VIEW shows every boat with her track and CPA ring and injects what the day does not give: 🌫 FOG, 🌬 WIND, ⚙ ENGINE FAILURE, ❚❚ PAUSE ALL, a message to one or all; ▤ SUMMARY prints each student's results. Students run shared scenarios for free.

Where she fits

The CTV is one of the working vessels: ⛽ OFFSHORE is hers, shared with the PSV, the 80 m supply vessel with its five DP exercises. Beside them stand ⚑ PILOT, ⛓ TOWING and ≋ SURVEY. A game controller steers her too. The ECDIS chart plotter unit is a separate route-planning exercise; the big ships have wings and LOOK AFT; ELEONORA has ⛵ REGATTA THE BALTIC LAP — the first lap; the next will be somewhere else in the world, and the race tells you about every place you pass (the mark cards).

Who it is for

Professional and leisure alike. The cadet before the first watch, the deck officer, the pilot, the tug, offshore or survey crew, the training centre that wants a situation every student can repeat — and, on the same sea, the leisure skipper who is curious how the working boats are handled and what the ship on the horizon can and cannot do. The vessel, the sea and the rules are the same for everyone; only the exercises are the professional's.

How to start

Free Mode is open to everyone — no account needed — with the 15 m motor yacht and the 50 ft cruiser LATEKO at up to TIME ×10; every other vessel — the CTV and the other working vessels among them — the docking, sailing and ECDIS units, the scenario builder and Classroom TEACH come with the simulator subscription; students join shared scenarios free. SHARED SEA and the regatta need a free SkipperCheck login. Our main product is the VHF course (€199) at /vhf-course: the certificate comes from the course, the practice from the simulator.

FAQ

Does it run on a Mac or a phone?

Yes — a browser page on Mac, Windows, Chromebook, iPad or phone, nothing to install.

Is the wind real?

Yes, MET Norway's real forecast for where your boat is. The two judged push-ons set their own wind, sea and current so every run is comparable; the real weather comes back afterwards.

Can I sail with friends?

Yes. In the SHARED SEA you meet other skippers in real time; a class puts your group on a private sea.

Can a school use it?

Yes. An instructor opens a class with TEACH, students join with a code or a link, up to 30 at a time.

Do I get a certificate?

The VHF course gives the certificate. The simulator gives practice, scores and stars — and a demo skipper to learn from.

Take the CTV out to B2-H8 now: /colreg-simulator?scenario=familiarization&area=gulf-of-riga&vessel=ctv — and start with the VHF course at /vhf-course.

Related reading

• Offshore simulator — PSV dynamic positioning at a platform and CTV push-on transfers at a wind turbine, in the browser
• Platform supply vessel simulator — DP, the joystick and the 500 m zone, in the browser
• Survey catamaran simulator — multibeam lines, the SV cast and DP track-keeping, in the browser
• All articles · Open the simulator

Boat types are described generically; SkipperCheck is not affiliated with any boat builder or class association.