Carina's Mechanical Systems

My apologies if this is too technical or detailed. 
Double click photos to enlarge

Mast and Rig:
  • The sail rig is a fractional rigged sloop design with head stay, two swept back shrouds and a simple diamond rig - all 7/16" dia. wire. The spar and boom are beefy aluminum Kenyon extrusions custom fabricated by JSI of St. Pete's, FL. 

  • A Dutchman boom brake controls against uncontrollable jibes.
  • A Garhauer boom vang supports the boom without need for topping lift and is all that is needed to control sail twist. There is no traveler.
  • All lines and sheets lead to a single electric winch at the helm for single-handed use.
  • The sails were fabricated at JSI / Doyle sails – St. Pete’s FL.

  • Main sail: The main sail is a full roach, full batten, 6 oz. Dacron sail with single line slab reefing set up with 3 reefing points.

  • Jib: Rather than the typical roller furling headsail, Manta uses a full batten hanked-on 90% jib. A jib downhaul line leads aft to the portside rail to help drop the jib into lazy jacks. This jib design is unconventional compared to the typical furled head sails but it does make for a bullet-proof sail design. There are no jib sheets as typical on an overlapping genoa with roller furling and tacking is incredibly simple.

  • Manta is one of the few boats that uses a camber spar. This is essentially a curved boom inserted through a sleeve above the foot of the jib. It’s similar to the Hoyt jib boom for its self-tacking qualities and eliminating flogging, but it goes a step further; The camber spar maintains an induced camber & stable draft so you can sail more efficiently when reaching or running. Wing-on wing downwind sailing is an ease. In winds above 20 knots the jib is much safer and controllable than a conventional roller furled overlapping genoa head sail.

  • We have a 1.5 oz. Nylon UPS reaching spinnaker set on a Facnor continuous line furler that is most optimum for sailing between 90 degrees -140 degrees in apparent wind up to 10-12 Kts.   

  • The cockpit hardtop roof and radar arch is a work of art fabricated from aluminum tubular material with an antiskid surfaced fiberglass roof panel. It’s a feature distinctive to Manta and offers an excellent platform for mounting the 6 solar panels as well as accessing the sail. The radar arch, positioned about 18’ above water surface, allows ample space for mounting of the radar dome and VHF, Cellular, Wi-Fi, GPS and Sirius satellite antennas. The arch also supports our dinghy and outboard motor on 6:1 block & tackle for raising/ lowering. The cockpit is able to be fully enclosed from the elements with perimeter roll-up curtains.

  • 2 - 30 hp Volvo Penta D1-30 diesel engines provide auxiliary propulsion at average speed of 7.3 kts under both engines or 5.8 kts under single engine while consuming ¾ gal of fuel/ motor/hour. If light winds and we have to be somewhere, we’ll often motor sail on just one of the engines to boost our speed while still limiting fuel consumption.
  • The props are Volvo Penta 3-blade feathering props with rope cutters.

  • A 120 gal aluminum fuel tank is located under the port cockpit floor providing diesel fuel to both engines and the generator. Each engine has its own 2ndry canister fuel filters but the primary fuel filtration is through a Puretec centrifugal system. By closing a two-way fuel valve and activating a manual timer that controls a separate electric fuel pump, the system can purify the entire tank of fuel from any potential accumulations of water, algea or sludge in a few hours. 

  • Engines are located under each berth and maintenance access is superb. Each engine has its own Reverso oil sump pump for quick oil changes. Speedseal Impeller plates aid in quick access to replace the raw water impellers. Engines have 115 amp alternators coupled to Balmar ARS-5 multistage battery regulators.

  • A Next-Gen 5.5KW diesel generator, located in the forward port locker, provides 110VAC power. The start-up switch is located at the main circuit breaker panel in the salon. The generator is relatively quiet in it's sound enclosure, but as a result produces much heat. 12V powered blowers are necessary to push / pull air through the sound enclosure to control engine temperature. In 2013 I purchased new Shurflo 4" blowers and increased all vent openings, blower hose, blast gates, and fittings to 4" diameter which has greatly improved air flow capacity. The blowers are now wired back to an independent breaker switch so blowers can be manually operated for further cool-down after generator is shut-off.   

Electrical Systems:
  • The Manta’s factory-equipped electrical system is extremely well-engineered with all electrical components fully integrated. Wiring is of proper conductor sizing, labeled and routed in chases throughout. All equipment onboard is powered by 12v source with the exception of the 80amp battery charger, washer/ dryer, and the air conditioning coolant pump.

  • The house battery banks are located under the salon settee. The original six- 6V Lifeline AGM batteries were replaced after 6 year's  use in Dec. 2012 with Trojan T-145plus wet cell batteries for less than 1/2 the cost of new AGM's. We also increased our total house capacity from 660 Ah to 780 Ah (3 pairs of 260 Ah 6V batteries wired in series). Each engine is still operating on the original Lifeline AGM 12V starting batteries.

  • There is an emergency parallel switch at the helm that momentarily parallels the 2 engine starting batteries to the house batteries if any one battery is low.

  • A Wells battery combiner combines any battery voltage charge from any of the 3 sources of charging – engine alternators, solar panels, battery charger (110V power from either shore power or generator). If house battery voltage drops below 12.6V the starter batteries are automatically disconnected from the combiner to retain their charge.
  • Voltage/ Amperage consumption of the house battery bank is monitored through a Xantrex LinkPro battery monitor.
  • 6 - 72 watt photovoltaic panels, and 2 additional 100 watt panels installed in 2014,  for a total output of 632 watts are mounted on the cockpit roof. A Blue Sky Solar Boost 50 regulates the charging.
  • A 2000 watt inverter converts 12V house battery to 110V AC for powering electrical appliances (i.e. toaster, microwave, blender, TV, ink jet printer, etc.).
  •  The 80 amp battery charger operates on 110v power off either shore power connections or generator.

  • Other misc. installed electrical equipment: AC/ Generator transfer switch, Yachtguard lightning and surge suppressors, ProMariner 60amp galvanic isolator.

  • The Manta fridge / freezer is a well engineered, custom fabricated top loading, side by side fridge / freezer with 6” of insulation surrounding the entire compartment making it extremely energy efficient. The evaporator plate is located in the freezer compartment with a spillover fan into the fridge compartment. The air cooled refrigeration compressor operates on 12V power and each compartment has it's own separate digital thermostatic controls. We typically have to defrost the unit every 8 weeks.

  • A 100 gal aluminum water tank is located under the starboard side of the cockpit floor. There is also another 11 gal of tank capacity within the hot water heater. 

  • The area under the starboard fore berth contains most of the boat's plumbing system. Similar to the engine compartment access, walk-in access for servicing pumps, sea cocks, filters, etc is excellent. These include: an Isotemp 11 gallon hot water heater (with heat exchanger from stbd engine coolant); A variable pressure fresh water pump. A 2" Groco raw water strainer is plumbed to 3 separate ports to an anchor wash down pump, the air conditioning coolant pump, and the generator raw water intake hose. 
  • Watermaker: We had no need to purchase, operate or maintain a complex watermaker while we have lived dockside or only made short duration trips during the first 4 years. In 2009, preparing for full time cruising, we purchased and self-installed a Spectra Catalina 300 MKII desalinator. It also is extremely efficient to operate, consuming about 15Amp hours of voltage while producing about 11-13 gal / hour of water.

Air Conditioning:
  • We have two separate reverse cycle air conditioners on board for either cooling or heat. Both are Cruise-Air / Dometic units. A 16000BTU unit for the salon and both forward portions of both hulls. A 12000BTU unit for both aft staterooms. The air conditioners and the raw water coolant pump operate on 110V AC so we have to be either plugged into shore power or use the 110V diesel generator. We've never used it while swinging on an anchor pointing into the wind as there is typically enough breeze to keep us cool without need for any air conditioner.

Washer/ Dryer:
  • We have the Splendide 2100 combo washer and dryer. This unit also only operates on 110V AC current. It's not super large, but will handle a full set of queen size bed sheets in the drum. We'll typically run 2-3 loads weekly and let the clothes air dry on the deck.


We upgraded our various communications systems summer 2013.
  • Cell Phone: We replaced our old hardwired the Motorola M-900 cell phone that used a signal booster amplifier connected to a 8’ antenna mounted on the radar arch. In it's place we installed a Digital Antenna cellular repeater. An internal antenna in salon amplifies cell phone signal to a external antenna on radar arch. As a result we can use the cell repeater for boosting cell signals for our phone, iPad and laptop aircard.
  • Internet Access: We purchased an unlocked iPad 4 w/ cellular & wifi and an unlocked Sierra Wireless Momentum USB Mobile Hotspot. Both units use AT&T data plans while in the States and BTC data plan in the Bahamas by swapping sim cards. Will work with any GSM cell systems.
  • Wi-Fi: We replaced the 5-Mile Wi-Fi with a Bitstorm Badboy Extreme WiFi and there Unleashed Router. Connections over  the Badboy's PoE Ethernet cable are superior to the 5 Mile's USB connection. The router allows wifi access for both laptop, iPad and iPhone from one source anywhere onboard. 
  • SSB / Sat Phone: We have only relied upon a Grundig SSB receiver with an external antenna cable up the stbd pennant halyard. This has suited our needs while cruising in the Bahamas. We will weigh the need for installing an SSB Transceiver or Iridium satellite phone if we venture into the Caribbean.
 Electronics System:
All electronic navigation components are Raymarine, interfaced in a fully integrated system unless otherwise noted.
  • E-120 Chartplotter w/ Navionics Platinum ENC’s
  • Sirius Weather for US coast wise
  • AIS Transceiver
  • 4 Kw Radar
  • Autopilot Linear Drive w/ wireless remote
  • DSM300 depth sounder
  • Air/ Wind Speed/ Log
  • VHF – Standard Horizon Phantom 2000
  • Clarion stereo with Bose exterior speakers in cockpit
  • Sharp Aquos 20” flat screen TV. Glomax TV antenna atop masthead
  • Media Player with 1TB external Hardrive for downloaded movies
  • The TV compartment behind the flat screen TV has been adapted to house the Clarion DVD changer, Media Player, DVD player, Digital/ analog TV converter, Printer/scanner, 12 volt RF remote controller. The Digital Antenna cellular repeater amp is also located in this compartment.

Light Fixtures:
  • Perko LED Running lights and Orca Green combo LED Tri-color / PV controlled anchor light. 
  • Interior and cockpit lighting are Taylorbrite CCD fluorescent fixtures that consume 0.5 Ah per fixture.
  • Hella LED spot lighting for berth and galley stove top task lighting. 
  • 7 Hella turbo fans throughout the boat provide ventilation while only consuming 1/10th of an Amp hr / fan.
  • Maxwell 1200 vertical windlass with combo chain/ rode capstan drive.
  • Rockna 55lb primary anchor. We replaced the original stainless steel chain in October 2014 with new ACCU - Peerless 5/16" G-4 galvanized chain.
  • 2ndry anchor is original factory supplied Spade A140 38 lb aluminum with 200’ 5/8” diameter, 8-ply nylon brait with 30’ of 5/16” chain rode.
  • 3rd anchor is a Fortress FX23 aluminum also with a 3rd  additional 200’ 5/8” diameter, 8-ply nylon brait with 30’ of 5/16” chain rode.
Safety Features / Equipment:
  • ACR search light with remote helm control.
  • Ditch bag with EPIRB, portable VHF radio, portable GPS, 1st aid kits.
  • Inflatable PFD’s with harnesses
  • Rigging wire cutters
  • 2 10lb Halon fire extinguishers
  • Fog horn / hailer on VHF radio
  • Drogue 
Lightning protection:
  • Knock on fiberglass… we’ve not been struck by lightning YET, although it’s been too close for comfort more times than we want to count. Manta has proactively provided various products as standard equipment that (theoretically at least) reduce the incident of direct lightning strikes to the aluminum mast that stands 62’ above the water.
  • What looks like a metal brush atop the mast is a Forespar static dissipator. It’s supposed to reduce the build-up of static ground charge and retard the formation of the ion “streamers” which complete the path for a lightning strike.
  • Also factory installed was the Strikeshield mast grounding system  (Has now gone out-of-business).The logic is if / when lightning does strike the mast, the electrical charge will seek a path to water through a highly conductive air terminal rod that extends above all other equipment atop the mast. The electrical charge will then travel down the aluminum mast to a tinned copper contact plate at the mast base. A heavy gauge copper conductor cable with an electrode that hangs overboard between the hulls, submerged in water can be easily clamped to the mast connection plate during approaching T-storms.
  • Lastly the tubular aluminum hardtop frame offers a Faraday cage kind-of- zone-of-protection.
  • All this being said we know of multiple folks sailing similarly equipped Mantas that have been struck by lightning resulting in fried electronics. Needless to say, we stay away from the mast during T-storms. We have no SSB copper grounding and our Marelon thru-hull fittings are not electrically bonded to the boats electrical ground system. Likewise, our aluminum sail drives / propellers are electrically isolated from our engine's electric ground.  Thus the Strikeshield system really offers the best means for any potential lightning strike to reach a path to water without blowing a catastrophic hole through our hulls. 
In all frankness, I’ll give you some of the negatives of the Manta Sailcat as well:

  • 1st, the bridge deck clearance (height of underside of boat above water between the hulls) is not best at about 24” and we'll get our share of wave slap. But again, hard to increase clearance in a cat of our size range. Thankfully, the shallow clearance is more to the aft with ample clearance forward between the bows. Also, the rounded hull underside helps minimize the wave slap. It's a design trade-off because to increase bridge deck clearance you would have to either raise the deck heights correspondingly which will then increase windage, or alternatively, you would have to lower the interior headroom (which is already at 6’3”). There's no perfect solution.
  • 2ndly, while the hull layup, structural construction and electrical systems were not compromised, I feel the finish workmanship by semi-skilled, low-paid factory workers was sloppy and rushed. I spent much of the first 4 years fixing or repairing many of the (mostly cosmetic) errors.
  • 3rd We were hull # 108 of what can only be assumed to be a very-used set of hull molds that initially started as a 38' cat, then was modified to a 40' cat and finally to the 42' cat version. The factory had to  perform a lot of gel coat and surface patches in many areas that have aged in the sunlight and are cosmetically quite evident.