For those who are really serious about being seen at a distance, nothing is going to work better than the Highland Giant Surface Marker Tube. This is BIG, { 10 ft | 3.0 m } tall and { 11 in | 28 cm } wide. There are three large bands of U.S Coast Guard approved 3M SOLAS (Safety Of Life At Sea) reflective tape to enhance surface visibility in marine environments. The marker includes a stainless steel D-ring at the top to attache a strobe and also has an elastic loop to hold a chemical light stick. Includes a special wider 6.5-inch X 14-inch all-mesh carry sleeve for backplate attachment.

The semi-closed design is a hybrid of open and closed types that can be used two different ways:

• The tube is open at the bottom as with the lift bag and incorporates an funnel-shaped (aka 'duck-bill') internal baffle that allows the tube to be inflated as usual with a regulator second stage at depth, but prevents the tube from unintentionally deflating should it fall over while on the surface.


• The tube also has an oral/power inflator that allows the tube to be inflated at the surface or at depth. Perfect for rebreather divers, using the oral/power inflator with the low pressure hose on a bailout bottle makes inflation manageable without the use of diluent gas.

The hybrid marking tube includes a compact over pressure valve to allow excess gas to vent during ascent and pull dump to deflate the bag before boarding the boat or when being rolled up for storage.

NOTE: The hybrid marking bag is not fully closed by design and if you inflate it when dry (i.e. at home, to 'test' it), you will discover gas slowly leaks out through the bottom baffle. This does not cause a problem in actual in-water use, where the water will cause the baffle to seal. Although the marking tube should NOT be used as a lift bag, for emergency purposes a fully inflated tube may be considered to have approximately { 75 lb | 34 kg } of lift when completely submerged.