These units have a floating housing and a fixed weir. The weir is typically a round dish and the height is adjusted up and down manually, often on a thread. Often, floating weir skimmers, whether they are fixed ring or self-adjusting, will have come with the pump attached to the skimmer body rather than remotely located. A disadvantages of this type is that the entire skimmer must be withdrawn from the pit in order to perform pump maintenance, and in the case of inaccessible or hazardous pits this can create OH&S issues.

Advantages:

• Medium (with pump) to Low cost
• Easily to deploy (without pump)
• High oil removal rates
• Able to "pull" oil from further distances on water surface

Disadvantages:

• Skim height needs continual manual readjustment - operator time and money
• Operator attention requirements may cause Occupational Health and Safety concerns 
• Affected by debris
• Oil collected can contain high water % 
• Very difficult to service pump - if supplied