A harness plug and methods of use. Example devices include an arcuate portion and a lateral portion disposed at an outer periphery of the arcuate portion. The arcuate portion is configured to engage with arcuate portion of a hole within a spacer. A method of using the harness plug includes molding a harness plug about a portion of a cable bundle and inserting the cable bundle into an arcuate portion of a hole in the spacer through a lateral portion of the first hole. The harness plug is pressed into the arcuate portion of a hole in the spacer. A streamer spacer for use with the harness plug includes a hole having a portion having an arcuate shape and a second portion lateral to and abutting the arcuate portion and extending to a periphery of an elongate body of the streamer spacer.