Semi closed surface marker bouy. The bouy automatically closes when it's filled with air which makes accidental draining of air impossible. The bouy has a combined over pressure and exhaust valve.

Made out of a durable yet smooth 210 deniers nylon material, ultrasonicly welded. The SMB has a trimming ribbon all around the edges.

The SMB has a small lead insert in the bottom to make ceratin it has an upright position in the surface. Overall length 125cm, 4' 2"