Lobster 31


In my vision Lobster 31 is the perfect choice for an experienced owner, who has gained a good boating career and has focussed perfectly what he needs from his boat, an owner who will hardly be satisfied from a world of  pre-packaged mass-production GRP boats.

TECHNICAL SPECIFICATIONS DOWNLOADS
Overall lenght: 8.50 m Top speed: 26-28 knots (depends on powerplant)
Hull lenght: 8.24 m Light displacement: 2250 kg
Maximum beam: 2.77 m Design displacement: 3000 kg
Height on DWL: 2.55 m Maximum displacement: 3800 kg
Draft: 0.98 m Fuel: 300 liters
Powerplant: single engine up to 160 HP, double engine up to 2 x 120 HP Freshwater: 140 litres
Cruise speed: 18-20 knots (depends on powerplant) Range: 250 NM

Lobster 31 originates form the request of a craftman’s owned boatyard near Venice (www.bremarine.com): he needs to have a design for a wooden boat with quite traditional lines that can merge a 3d modern design approach with the glamour of a classical looking wooden boat.

I developed a design which features modern wood & epoxy structures, with a lot of structural parts that can be CNC routed form solid wood planks or marine plywood sheets, thus giving the craftsman a solid and reliable base to work.

The name “Lobster” suggests an entire universe of sturdy and reliable working boats.

In my vision Lobster 31 is the perfect choice for an expterienced owner, who has gained a good boating experience and has focussed perfectly what he needs from his boat, a owner who will hardly be satisfied from a world of pre-packaged mass-production GRP boats.

Engine and performances

Lobster 31 can be powered with a wide choice of diesel inboard engines, in both configuration, single engine (max. 160 HP) or double engine (max 2 x 120 HP) , fitted with shaft drive and three-four blades bronze propellers. In the development stage of the project we simulated in 3d the pre-installation of the most widespread engines in european market to make sure that they fitted in engine room: Volvo Penta, Yanmar, Hyunday Seasall, Nanni diesel, Lombardini.

All these engines are reliable, modern, turbocharged compact engines that guarantee a good level of comfort during the travel, according you’re not too much in a hurry.

Maximum speed depends on engines fitted on board, with a peak speed around 28 knots with maximum power fitted; anyway Lobster is not made to rush in flat seas, her Vee hull gives his best in sailing through moderate weather with a good pace, achieving a good navigation comfort.

Hull is a classical moderate Vee one, with sprayrails and a skeg to protect shafts and propellers. I deliberately sacrified some knots of top speed to have a hull that gives us better perfomance in moderately rough seas.

Fuel use rate will be tipically in the range of 35 liters/hours with 2×120 engines at 23-24 knots, and 26 liters /hour with a 160 HP single engine at 21-22 knots ; a tipical range at cruise speed (15-17 knots) will be around 250 NM (with 300 liters tanks fitted) , giving you the freedom to plan a quite long range cruise.

Design and structural features

In the modern wooden boat cocept, that will be better called “wooden composite construction”, most of the less appreciated aspects of wood are not present, and wood can display its advantages in terms of lightness, flexibility, strenght, added to its timeless glamour, without the concerns of rotten wood, headache maintenance, shrinking and expansions of wood every season, periodical caulking leakages, stinky bilges and so on.

Lobster’s project originates in a 3D CAD environment; this emplies one more advantage: we can taylor each boat to owner’s needs to a level which is unachievable to a GRP boat.

The hull structures in based on 9 structural bulkheads, in marine grade 20 mm plywood strengthened by laminated solid wood elements; bulkheads are linked with a grid of solid wood longitudinal stringers, four of them working as engine beds. Planking is made by 18 mm plywood panels glued on the structure with epoxy resins; chines are reinforced with multiaxial glass fabrics laminated with epoxy; the whole hull built in this way behaves as a composite monocoque, much more similar to a composite structures than to a classical carvel planked boat.

Cabin , cockpit and other structure follow the same philosophy with a structural wooden grid and plywood panels glued on it to achieve a stiffen and light structure.

Interiors

Lobster 31 is a quite roomy boat for her dimensions.

Starting form the stern, we have a wide cockpit, with a central port to the sea (a stern platform is available as optional); cockpit can be arranged depending on the prevalent duty of the boat: simple pleasure craft, sport fishing boat.

Fixed or deployable seats, fishing rod holder, outriggers for big game fishing, the flexible strucure allows a wide range of solutions.

Quarter sawn teak is the natural choice for planking the floor of the cockpit, such as for the passageway to the bow and the bow area itself.

Going ahead form the cockpit we find a 15 cm step wich lead to the main deck cabin (about 1.9 m ceiling height) entrance, closed with a wood and glass door; entering the cabin we find a couch 1.5 meters long on the left side (may be converted in a single berth 1.8 metes long), and a galley area in front of it, with gas or electric stoves, a double SS steel sink with cold and hot water and the 80 liters fridge, whose cap work as a working plane.

In the forward part of cabin we find the pilot seat on the right side, and the copilot position on the left; pilot seat is folding, since in low visibility or rough conditions most pilots prefers to steer the boat standing upright; a complete suite of instruments is in the pilot’s line of sight including engine instruments, navigation plotter, windlass, horn and wipers switches, VHF radio, log, sea temperatures e depth gauges, and so on. VHF radio is fitted on the ceiling in the central part of the cabin, so that can be operated both by pilot and copilot if needed; ss steel engine throttle are on the right side of the cabin , sturdily fitted on the cabin structure and on the right hand of the pilot with a simple move. Cabin is in a quite high position , this allows the pilot to have a very good visibility right few meters ahead of the bow, both at low speed and when boat is planing.

In the middle of bulkhead a two-steps stair leads to the lower deck cabin, which features a huge V-shaped double berth, a separate toilet area on the left side, with a electrical wc, a small sink and a shower ; and some lockers.

Some lateral LED small spotlights and a large hatch on the ceiling give this room a good light.

Going back to the deck, the bow area is quite large, passing from the cockpit to the bow is absolutely safe even in rough conditions, the sturdy steel handrail allows a confident move along the side of the boat.

Systems

Lobster will be fitted with 12 V electrical systems, service battery pack and engine start battery will recharged via engine’s alternator managed by an electronic smart charger that will feed batteries with proper tension guaranteeing them a long life.

An electrical panel will be located in the main deck cabin to manage all the electrical loads on board and have always the battery situation under the eye; each cable will be marked and its path will be reported in a system book, delivered to the owner after boat’s launch and sea trials, to have a clear situation of the whole electrical system if needed.

A 220 V plug will be fitted in stern area to charge batteries when moored in marina; a small 220V inverter will be on board feeding a plug in the lower deck cabin and one or more in the main deck cabin, something useful to charge small devices, mobile phones, tablets and so on.

White water system will be based on a 140 litres thermoplastic tank, feeding all the sinks via an autoclave ; a inlet direct from the sea will provide seawater for all the usage where freshwater is not mandatory, a small watermaker unit can be fitted on board.

Black water will be stored in a dedicated 40 liters tank with anti-smell filters, to be unloaded in harbour as by actual european rules.

An hydraulic box will manage everything onboard needing hydraulic oil under pressure, typically the rudder controls and the stern flaps.

Building plans

Lobster 31 arises as a project for boatyards, wich normally requires a less detailed set of drawings compared to a homebuilder; I personally consider an enterprise like building this boat on the top edge of what a homebuilder can do, more because of systems complexity than for the hull building.

September 2017 update:

I’ m currently revising the project in order to publish a set of plans specifically dedicated to homebuilders, with the additional chance to have a powerplant based on a single or double four strokes outboard engines too; if you’re interested in Lobster 31 building plans please send me an e-mail.