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What I learned today in Marine Systems Class - davesbrain — LiveJournal
What I learned today in Marine Systems Class

  • some larger systems have a heater pass through from engine, to provide warm water at tap

  • some larger systems have an expansion/accumulator tank so pump doesn;t have to run every time

  • all tanks should have a venting system

  • all tanks should be easily cleanable

  • what type of pump do I have? electric? hand pump?

  • even in Great Lakes, many greywater systems drain overboard

  • in most places, it is illegal to have a blackwater dump, but still legal for a greywater dump

  • not in G.L. even greywater dump is illegal

  • in fact, any system whereby blackwater can be dumped overboardf (and that includes a porta-potty) is illegal (this is why the super-inconvenient vacuum system is used!)

  • Y-valves can be used offshore (bluewater, > 7 miles)

  • generally, do not trust tank water for drinking


  • don't use any solvents or cleaner in head - will degrade pipes

  • use baking soda, vinegar, marine grade antifreeze

  • Head cocktail: 1/2 L vinegar, flush, 1/2L vegetable oil, flush (lubricates O-rings, coats walls)

  • be gentle with hand pump , don't use full up/down strokes - it'll last longer

Bilge Pump

  • wise to place manual bilge pump in cockpit so can be on-deck and still pumping

  • elec. bilge pump should bypass panel

  • when chartering, don't assume pump works - dump  a few buckets in bilge, test outflow

  • check how effective elec. pump is re:

  • leak inflow rate

  • battery capacity

  • check how effective manual pump is re:

  • outflow rate

  • manual capacity

  • most sinking (80%) is via through hull leaks, and most (80%) is after bilge pump runs down battery

  • check: water in bilge? empty to form bsaseline, strainer clear? bilge free of debris? fittings secure? do hard test w/ water


  • solid fuel, diesel, propane - none use electricity

  • A/C

  • electrical are usually too consumptive to be effective unless on shore power

  • other types are seawater


  • I have 0/A/B/A+B switcher

  • good method: start engine on A, run for 5 minutes to recharge, then switch to B, run all house power off B

  • better to switch only when running at low idle

  • deep cycle battery is meant for house, std. battery has high cranking amps for engine

  • other optinos are GEL batteries - safer, sealed, but more $$

  • AGMs are even safer, very efficent and last much longer

  • however, sholdn't mix type - chargers prefer onny one type - amnd a smart charger will allow you toprogram which type

  • solar panels are a great option for keeping batteries charged, but efficiency is greatly reduced with shade or poor angle to sun

  • wise to keep battery top clean - discourages trickle discharge


  • industry switching over to LEDs, much more efficient

  • conversion is easy


  • should have its own panel

  • 55% of boat fires are electrical (shorts, overloads), 24% engine, 5% fuel leaks, only 1% alcohol stoves


  • alcohol stove do not normally explode (unless somehow contained)

  • alcohol fire is invisible

  • unlike others, alcohol fire can be doused with water

  • keep a pot of water handy when cooking w/ alcohol


  • mark rode, chain with zip ties at depths


  • use floating line for painter so as not to foul prop

  • good engines: gas engine w/ integral tank, or TORQEDO (electric)

  • small electric motor is not recommended

  • at night, secure dinghy so it does not bump hull

  • tie to rode so it can swing freely

  • tie to boom, tie off boom 90 degrees

  • raft securely alongside hull or on dock

  • in Caribbean, dinghy theft is #1 crime - use a lock for boat and motor or haul aboard


  • make a hush box

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