On March 18th, USA Swimming released the following statement regarding the use of multiple swimsuits in competition.

There have recently been a number of questions regarding the use of two swimsuits during competition. Although the USA Swimming Rules & Regulations do not specifically address this, FINA has interpreted its General Rule GR 5.3 to allow the use of only one swimsuit during competition. Our Rules & Regulations require that USA Swimming’s technical swimming rules conform to those of FINA. In order for our interpretation to conform to that used by FINA, the following interpretation is being made, effective immediately.

For purposes of Article 102.9 of the USA Swimming Rules & Regulations, Swimwear, the use of more than one swimsuit at a time during any USA Swimming sanctioned or approved competition is prohibited.