Lm Mermaid 315

LM Mermaid 315

The LM Mermaid 315 is a rare Danish cruiser‑motorsailer that quietly reworks the successful LM 30 hull into a more conventional family yacht. Built in the mid‑1980s in only about 65 examples, it has become a connoisseur’s boat on the second‑hand market, prized more for solidity and comfort than for speed. Her hand‑laid fibreglass construction, insulated sandwich deck and modest rig create a pocket motorsailer that is happiest mixing sail and engine on settled coastal passages. This report sketches how the Mermaid 315 emerged from LM’s motorsailer lineage, how her variants were configured, and why she retains a quiet but loyal following today.

Origins and Design

The Mermaid 315 was designed by Danish naval architect Bent Juul Andersen and built by LM Glasfiber A/S between 1983 and 1989, a relatively short production window that already marks her as a niche model. According to a specifications database, she measures 9.35 m overall with an 8.0 m waterline, 3.05 m beam and about 1.59 m draft, dimensions that align closely with figures published for the LM 30 and support the view that she uses the same underwater shape. A sailboat directory explicitly notes that the Mermaid 315 shares its fin‑keel, skeg‑hung rudder hull with the LM 30, but carries a different deck and rig concept aimed at more traditional cruising rather than a full motorsailer wheelhouse. Brokers’ notes and review articles agree that LM completed roughly 65 hulls during this six‑year run, a tiny fraction of the 311 LM 30s built over more than a decade, which helps explain why even experienced sailors often struggle to find detailed information about the type. In that sense the Mermaid 315 can be seen as LM’s quiet experiment: a conventional‑looking 30‑footer derived from a proven motorsailer platform, built in small numbers for a specific coastal‑cruising clientele.

Construction and Variants

The hull of the Mermaid 315 is described in multiple reviews as hand‑laid solid GRP, a traditional LM approach that favours durability over minimum weight. Her deck follows LM’s characteristic insulated sandwich concept, with a fibreglass outer skin and core material designed both to stiffen the cabin roof and to limit condensation inside the accommodation, a practical touch for cool northern climates. Displacement is reported around 4,800–5,000 kg with ballast about 1,900 kg, giving a ballast‑to‑displacement ratio near (0.40), which reviewers interpret as evidence of a stable, stiff boat rather than a lightly ballasted sprinter. Calculated displacement–length ratios around (259)–(261) and immersion figures approaching 927 lb per inch further underline that this is a heavy cruising hull that reacts slowly and predictably, reinforcing the motorsailer rather than performance‑cruiser identity. LM also offered the Mermaid 315 with different keel alternatives and even different ballast materials, with at least some builds using lead instead of the more common iron, so individual boats can vary significantly beneath the waterline and buyers are routinely advised to verify exactly which configuration a given hull carries.

Rig, Engine and Performance

Technically, the Mermaid 315 is a masthead sloop carrying about (441\ \text{ft}^2) of working sail between mainsail and headsail, a figure that places her on the modest side for a 30‑foot cruiser of this weight. A sailmaker’s rig plan gives mainsail luff (P) around 11.21 m and foot (E) about 3.22 m, with headsail triangle dimensions (I) near 11.95 m and (J) roughly 3.19 m, outlining a compact, easily handled masthead rig well suited to short‑handed family crews. Under power she is typically fitted with a 20 hp Bukh DV20 diesel and saildrive, and one European review cites register figures of roughly 7.5 knots for a higher‑speed setup and about 5.2 knots for a lower‑speed gearing, both sitting comfortably around the theoretical hull speed of approximately 6.9 knots for her waterline length. Published calculations give a sail‑area‑to‑displacement ratio near (14.7) and a relative speed index around (21), numbers that reviewers use to classify the Mermaid 315 as slightly under‑powered under sail alone but very competent when sail and engine are combined. Comfort ratios around (27) and capsize screening values near (1.83) are quoted in several databases, and these conservative figures match sea‑going commentary that the boat feels stable and well‑mannered in a seaway rather than lively or quick to accelerate.

Interior, Use and Reputation

Below decks the Mermaid 315 follows LM tradition with a teak interior and a layout arranged to sleep up to six people, typically using a forward cabin, saloon berths and an additional berth aft. The plan includes a proper galley and separate heads compartment, and reviewers point out that the insulated sandwich deck and timber joinery help keep the cabin dry and warm on the chilly, damp coastal routes for which the boat was conceived. A detailed Danish broker’s sheet for a 1985 hull lists a fresh‑water tank of about 140 litres and a diesel tank of roughly 68 litres, capacities that align neatly with the idea of a small family cruiser able to spend several days away from shore power while mixing sailing and motoring. In one Svendborg listing a mid‑1980s Mermaid 315 is described as a well‑sailing, reliable and spacious family cruiser with a strong quality reputation, reflecting a broader marketplace view that LM’s workmanship in this era stood out among production builders. Online reviewers at Listings Port and similar communities tend to summarise the model as a scarce, solidly built Danish pocket motorsailer that sacrifices outright speed for comfort, quiet progress and the ability to carry a crew in reasonable shelter through changeable northern weather.

Market and Legacy

Compared with the 311‑boat production run of the LM 30 between 1977 and 1990, the Mermaid 315’s roughly 65 hulls make her an uncommon sight, and she appears only sporadically in brokerage listings outside Scandinavia. When she does come to market, databases usually show asking prices that reflect her niche status: above some older 27–28‑footers but below premium blue‑water brands, with condition and equipment levels varying widely because many examples have had long‑term owners. Review sites emphasise that, thanks to the shared hull with the LM 30, the Mermaid 315 benefits from proven underwater lines and a reputation for seakindly motion, even if her more modest rig and shorter production have kept her from gaining the same name recognition. On at least one Dutch sailing forum, contributors explicitly note how little hard information they can find about the type and remark that essentially a single in‑depth review seems to exist, a scarcity that has ironically added to the boat’s aura among enthusiasts who enjoy owning something a little off the mainstream. Taken together, the conservative numbers, sturdy construction, adaptable keel and engine options and small but loyal owner base suggest that the LM Mermaid 315’s legacy lies in offering a very Scandinavian blend of practicality, comfort and understated character on a proven 30‑foot hull, rather than in chasing fashion or racing silverware.