Dacorum Sub Aqua Club

Using the Club Boat

This page provides information about using the boat.

Safety

• inform the Coastguard or your shore cover of your intentions and latest return time. Contact them when you return
• always have the kill cord securely attached to the driver or the crew of the boat while the engine is running. There are spare kill cords under the seat and in the tools box. 
• there is an aerosol fog horn under the seat
• fit the A frame -mounted radar reflector before setting out
• check the weather - bad weather increases risks and fuel consumption
• estimate your fuel needs - carry the spare fuel tanks if in doubt
• check the time and heights of the tide to make sure you can launch and retrieve the boat and enter and leave harbour - harbour bars can be particularly dangerous at certain heights of tides

Fuel

• Petrol and oil
  • The boat uses unleaded petrol which is stored in 2 tanks in the console
  • The boat uses Mercury Optimax two stroke oil which is stored in an oil tank in front of the engine
• Main Tanks
  • There are two 45 litre tanks under the console
  • Each engine has its own tank.
  • There is a single fuel line leading to a priming bulb and fuel switch under the console seat
  • The switch that determines which of the two tanks the engine draws from
  • The tanks are vented via two pipe leading from the back of the console
  • Each tank has 3 small windows that act as contents gauges
  • Each tank has a filling cap located under the console seat
• Consumption
  • As the boat only does 4 miles to the gallon, at very best, care must be taken to make sure you don't run out of fuel
  • A rule of thumb for fuel consumption is based on how you drive the boat:
    • Optimum fuel efficiency is achieved at a speed slightly over planing speed. Planing (bouncing over the water at high speed) is much more fuel efficient than displacing water (pushing water out of the way of the hull at lower speeds)
    • If you plane at full throttle, you use 2 times as much fuel as the optimum
    • If you can't plane (in other words, the boat is forced to act as a displacement craft - perhaps because one engine has failed and you have not the power to plane), you use 4 times as much fuel as the optimum

• Range

In ideal conditions, with 6 divers, travelling just above planing speed, it should be possible to go 75 nm.

In rough conditions, with a greater load or if you cannot plane, your range will be much less.

It's a good idea to check that the tanks are full before setting out - not every one fills them to the brim.

• How to reduce the risk of running out of fuel

• Check the contents of the tanks before setting out.
• Bring the portable tanks.
• Plane if at all possible:
  • This can be difficult in big waves. The boat has to slow down to negotiate the crests of the waves.
  • It will be impossible to plane if the boat is overloaded.
• Don't use full throttle.

• If you do run out of fuel

• Consider putting down the anchor to prevent you drifting into danger or away from divers in the water
• Consider putting a lifting bag or bucket on the painter to hold the bows into the wind and waves
• Inform the Coastguard and nearby boats
  • If lack of power will leave the boat or crew in a dangerous situation or there are divers in the water - treat it as an emergency.
  • If no one is danger, you need to attract the attention of someone to tow you back to a safe harbour.
• Salvage
  • If a boat is rescued by another boat, the rescuer can claim compensation for risking his boat - possibly a big fraction of the value of the rescued boat
  • Agree the towing fee with the towing boat before towing - it would be reasonable to pay their extra fuel costs, at least. 
  • Always pass your towing line to the towing boat

Launching

• remove the trailer board, electric cable and the 2 main straps across the boat
• slacken the trailer board bars and slide them into the trailer
• raise the engine
• remove the side straps
• keep the winch strap and painter holding the boat to the trailer until the trailer is in the water
• two suited divers must be ready in the water to help launch. One holds the painter
• untie the painter and lower the boat into the water with the winch
• warn people outside the boat to stand clear when launching, retrieving or starting the engines
• don't allow the engine or the hull to ground as the boat is lowered
• don't allow the boat to float forward onto sharp parts of the trailer after launch
• move the boat into a safe location

Loading the boat

• the boat normally carries a maximum of 6 divers with cylinders for one dive
• secure cylinders on the bottle rack with bungees
• place soft equipment and weight belts in the front of the boat

Starting the engine

• before starting the engine, the water inlet near the propeller must be immersed in water
• if the boat is not in the water the engine must be connected to a water source using a pose pipe and the "ear muffs" or the flushing port
• prime the fuel using the rubber, bulb shaped, hand, fuel pump close to the engine
• insert the ignition key
• check the kill cord is inserted so the engine is able to start
• attach the kill cord to the boat handler
• check the engine in neutral
• check that no one is in the water at the back of the boat
• turn the key to operate the starter motor for up to 10 seconds

• to avoid damage to the water pump or the engine seizing due to lack of coolant, check the coolant tell tale immediately after starting the engine - stop the engine if there is no telltale

Using the Navigation Equipment

• GPS
  • The club boat is equipped with a Garmin 128 GPS. Follow this link to print a copy of its manual.
  • Take care with the survey Datum you use:
    • Datums are needed because the earth is not a true sphere 
    • It is important to check which Datum the GPS is set to before using it.
    • Most British charts use the Ordinance Survey of Great Britain 1936 (OSGB36/GBR36) datum.
    • Most GPS sets, straight out of the box,  use WGS 84 datum. 
    • OSGB charts have a Position Correction Factor offset printed on them which can be used to convert chart positions to WGS 84 positions. 
    • A WGS 84 position is 140 metres, 120^o from the same OSGB position.
    • Often positions taken from dive books are of unspecified Datum - we normally assume they are OSGB.  
  • Make sure the GPS "Units of Measurement" are Knots and Nautical Miles.

• Echo Sounder
  • The echo sounder is essential for the final stages of the location of most dive sites. 
  • Drive the boat slowly when searching.
  • Remember the echo sounder transducer is at the back of the boat, so the display shows what you have just passed.

• A paddlewheel on the transom measures the boat's speed through water and displays the result of a speedometer on the console.

• Magnetic Compass
When positioned on the console there is considerable deviation due to the boat's electrics and electronics, but the compass is removable and can easily be used accurately from other parts of the boat.

Mooring the boat

• make sure the boat is left in a safe location when you return to shore - one thing is certain, the tide will rise or fall!
• if the boat is moored or left at beach it should be supervised

Retrieving the boat

• when the engines are no longer needed, disconnect the fuel lines while the engines are running to run the engines dry of petrol
• when the engines have stopped, raise the engines
• unload people, cylinders and weight belts from the boat before retrieving
• wait until the tide has risen high enough to allow the trailer wheels into the water on the slip
• reverse the trailer down the slip. It must remain connected to the towing vehicle
• attach the winch strap
• ensure no one is behind the boat in case the winch or strap fails
• winch up the boat allowing excess water to drain rather than overload the winch
• before moving the trailer tie the painter to the trailer for extra security
• tow the trailer off the slip
• replace the trailer board, electric cable and the 2 main straps across the boat before taking the boat on the road

See the Hiring the Club boat and Club boat's equipment pages.