a0d72727_an_Inflatable_Dinghy_or_Tender__1
[Types of inflatable Dinghy] Inflatable roll up with inflatable keel [Example] Zodiac Air lite range 260 [1] 
An inflatable keel give some directional stability due to the underwater shape. Not as much as a RIB bottom but much more than a flat bottom
Choosing an Inflatable Dinghy or Tender
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