We offer buoyancy installations as well as inspection of current buoyancy!
Form of buoyancy for seagoing vessels
Buoyancy must consist of either foam or approved plastic bottles, or a combination of both. Buoyant material may not be affected by oil or oil products. Foam should be of a suitable closed cell type (usually a polyurethane type) and until such time as “approved” bottles are identified the only plastic bottles used should be “H.D.P.E.(High Density Polyethylene) Grade 2” plastic bottles with secure watertight caps, or sealed six-sided “boat floats” manufactured of H.D.P.E, designed specifically for the purpose of providing buoyancy in small vessels. Sufficient hatches are to be provided for inspection of the bottles.
Form of buoyancy for inland vessels
Although the same standards are recommended, the reality is that due to the variations of craft involved, strict adherence to the above mentioned standard is not required. A reasonable and appropriate effort should be made to ensure that the vessel cannot sink.
Amount of buoyancy to be provided
It should be obvious that a simple standard amount of buoyancy will not be appropriate as vessels are constructed of various materials such as steel, aluminium, or from lightweight and buoyant materials such as foam sandwich construction. An individual calculation has to be made in every case to ensure that the vessel achieves the desired platform. An industry norm has been developed where 60% built-in buoyancy has been shown to be sufficient on wood and GRP constructions. SAMSA accepts this standard on categories B, C, D and E vessels so constructed.
The 60% means the following:
The volume (Mass) of water displaced by the buoyancy (i.e. the foam or bottles) provided inside the vessel must represent a figure of 60% of the gross weight of the vessel. Gross weight means; the weight of the vessel, engines, stores, fuel, persons etc. (See a worked example on the SAMSA flotation certificate further down)
It is important to note however that this is only a tried and tested formula on the type of vessels for which it is intended, namely the mass of wood and GRP ski-boats which make up the majority of the vessels at sea.
Regarding category R vessels (inland waters) and the exempted vessels mentioned in regulation 27, SAMSA, in conjunction with the Boat Building Industry Association of South Africa (BIASA), has determined that sufficient buoyancy is provided to meet the requirements of the regulations when 30% of the vessel’s weight (weight of boat, engine, fuel, stores, equipment but not persons) is fitted as buoyancy. Once again, this refers to the common wood and GRP constructed vessels.
A different buoyancy requirement applies to inflatable vessels and the regulations require these vessels to have at least 3 compartments, the smallest of which must be able to keep the vessel afloat. Note, a rigid hull is not included in this calculation, and also that extreme uses of inflatable vessels for commercial use such as cargo carrying or the like may require additional buoyancy to the satisfaction of SAMSA, by way of foam filled hulls or additional compartments, as this was never the intention of this exception.
Vessels such as category C, D & E pleasure sailing vessels (yachts) are still exempted from buoyancy or carrying a life raft. They are required to carry life rings (1 per two persons) and operate no more than 30 miles from a safe haven during daylight hours (sunrise to sunset).
The “chukkies” or vessels described as “commercial small vessels, being fishing boats of more than 7 metres in overall length and of such heavy construction that the fitting of built-in buoyancy was impracticable”, were required to comply with the buoyancy requirements as of August 2009, or fit a liferaft. (See regulation 39(3).