A small sensor addressing a familiar yacht problem
Simarine's STR2 radar tank-level sender has been selected as a highlighted product on the METSTRADE 2026 exhibition website, giving a piece of relatively unglamorous equipment a prominent position ahead of the 17–19 November trade show in Amsterdam. For owners of 12–23.99-metre yachts, tank monitoring is a practical issue: a misread fresh-water, fuel or waste-tank level can affect itinerary choices and crew routines. The significance of STR2 is not a claim that it transforms a yacht's performance, but its method of reading fluid levels from outside a suitable tank. This report examines the manufacturer's technical information, including installation conditions that a convenient product description can obscure.
What the STR2 is and is not
Simarine describes two related radar devices, STR1 and STR2. Both use a non-contact micro-radar method to measure fluid height, but the outputs are different. STR1 is aimed at analogue gauge arrangements, while STR2 transmits tank-level data onto an NMEA 2000 network and also supports Bluetooth configuration. On a modern cruising yacht, that means a compatible multifunction display may be able to show levels alongside navigation and vessel data. It does not mean every plotter will instantly present the correct tank volume without setup. The underlying installation and calibration still matter, especially for tanks whose shape changes significantly from bottom to top.
The published measurement envelope
The manufacturer specifies tank heights of 150 to 2,000 millimetres for STR2, a resolution of approximately seven millimetres and a near-face dead zone of around ten millimetres. It lists a measurement update rate of half a hertz through the NMEA 2000 bus. These are device specifications rather than an independently verified accuracy claim for an arbitrary yacht tank. They can help a yard decide whether a particular installation is feasible, but the owner will still want to understand usable accuracy after calibration, especially near the empty or nearly full positions. The sensor is designed to read through suitable tank material, so a visually similar tank with a different construction can demand a different mounting approach.
Why a no-penetration mount appeals
A traditional sender often involves a tank opening, float, internal probe or other hardware that may be difficult to service. Simarine's radar approach is advertised as mounting externally on top of a suitable tank, using a peel-and-stick arrangement. On a mid-size yacht with tanks located beneath fitted joinery, reducing new penetrations can be useful, provided the sensor is reachable, the mounting surface is suitable and the installation follows the manual. It is particularly important to distinguish a new-build installation from a refit. On an older boat, even discovering what material the existing tank is made from can require documentation or careful inspection rather than assumptions based on an accessible lid.
Tank material is a real limit
The published specifications identify composite or glass-reinforced plastic tanks as appropriate, with an S5 metal-tank adapter for relevant metal installations. Simarine lists a maximum material thickness of ten millimetres in its general specification. This makes the product less universal than the headline phrase 'any tank shape' might suggest if read without the caveats. The geometry can be flexible, but physical material, wall thickness and access still need checking. Owners should ask a competent installer to confirm the proposed position and whether a metal adapter or flange is necessary. No one should drill or modify a fuel or waste tank simply to test compatibility without proper safety procedures and the tank builder's instructions.
NMEA 2000 is the practical dividing line
STR2's stated output is the standard NMEA 2000 fluid-level parameter group, PGN 127505. The manufacturer says the signal can be used by compatible displays, and its own information describes a dedicated backbone connector. A yacht owner should nevertheless confirm compatibility with the exact software and hardware version installed at the helm. Some displays can receive tank information but require custom configuration, while existing network configurations may already contain a sensor assigned to the same tank instance. That can cause confusing duplicate readings or incorrect labels if a refit is not planned properly. The professional installing STR2 should document the device instance, fluid type, calibration and displayed name.
A necessary certification footnote
One of the most important details in Simarine's product documentation is that NMEA 2000 certification for STR2 is described as pending. The device is marketed as using NMEA 2000 signalling, but users should not convert a 'pending' certification note into a claim that formal certification has already been completed. This distinction may matter to yachtbuilders, surveyors and owners who specify only certified network equipment. The appropriate step is to obtain the latest compliance and compatibility information from the manufacturer before purchase or fitment. The article reports the device's advertised capabilities, not an independent certification result or a promise that every chartplotter combination has been tested.
Calibration matters more than a tidy gauge
A tank-level sensor measures height, yet owners usually need a meaningful estimate of remaining litres or percentage capacity. A rectangular tank is relatively straightforward; irregular marine tanks have sloping surfaces, intrusions and varying cross-sections. Simarine says its application can use up to 100 calibration points, allowing a shape-specific relationship between measured height and displayed quantity. That capability is useful only if calibration is carried out against reliable physical volumes and recorded. A precise-looking digital display can still be systematically wrong when based on poor tank dimensions. For fuel planning or waste-disposal compliance, sensible margins remain essential regardless of how sophisticated the sensor looks at the helm.
Where the extra information may help
On a 12–23.99-metre motor yacht, the strongest uses are often mundane: deciding whether to refill water before an anchorage, checking a holding tank before a marina stay, or spotting a discrepancy between expected and reported fuel use. Those tasks do not require artificial intelligence or complex automation; they require trustworthy readings in a place where the skipper can see them. A sensor that communicates over an existing network can improve visibility, particularly if the boat already has integrated monitoring. Owners should avoid assuming the new system will automatically trigger alarms, remote notifications or maintenance records unless their wider onboard equipment supports those functions and has been configured to do so.
Power, protection and maintenance checks
The official product information gives a supply range of eight to 35 volts DC and an approximate draw of 14–20 milliamps at 12 volts. It also specifies IP67 protection and a three-year warranty. These details help installers assess electrical and environmental suitability, but the installation still needs appropriate fusing, network loading, cable protection and secure mounting. In particular, IP67 alone should not be interpreted as approval for unlimited immersion, a hazardous environment or any mounting orientation. A yacht's tank compartment may contain fumes, condensation, cleaning chemicals or vibration. Installers should review the complete manual and applicable safety standards rather than extrapolate from a marketing specification.
Price, availability and a balanced comparison
Simarine's current product page lists an advertised price for STR2 and shows it as available to order, but local taxes, distribution arrangements and installation charges may differ. Owners will be better served by comparing the installed cost against repairing an existing sender, not just the small device price. The old gauge might have adequate performance with a replacement cable or calibration; conversely, a difficult-to-reach probe may justify moving to an external sensor. Retrofitting a yacht is rarely priced by component alone. Time spent verifying tank dimensions, routing NMEA wiring and documenting the new sensor can exceed the cost of the hardware itself. This is an ownership calculation rather than a blanket recommendation.
What to ask in Amsterdam
A useful METSTRADE demonstration should show STR2 connected to a real NMEA 2000 display and should include a tank-shape calibration example, not only a perfect straight-sided test vessel. Visitors should ask about compatibility with their helm software, maximum tank-wall thickness, metal tank adapters, Bluetooth configuration, failure indication and the status of formal certification. For existing installations, bringing photographs of the tanks, any old sender and the current NMEA backbone can save a great deal of speculation. A knowledgeable surveyor or marine electrician can turn those observations into an appropriate installation plan. That is the level at which a highlighted product becomes a practical improvement rather than another purchase made on brochure appeal.
Source and editorial verification
This article is based on Simarine's own STR1/STR2 technical product information and installation manual, together with the METSTRADE 2026 organiser's product highlight and exhibition schedule. All numerical specifications are attributed to the manufacturer. The analysis is directed to the 12–23.99-metre luxury-yacht segment, but the sensor is not presented as exclusive to that segment or as already fitted to a named yacht. Installation recommendations are conditional on the boat's tank materials, dimensions and onboard network. Readers should verify current certification, compatibility and local availability before relying on an advertised feature for a safety-critical decision.
