The older style Perception-Dagger-Mainstream replacement hatch covers, both Round and Oval are discontinued! (See round hatch info below.)
The only current Oval option is to use the Perception Oval Hatch Cover or the Dagger Oval Hatch Cover. These are copies of the old style black hatch. It is assumed that the modern dual density will fit most of the older kayaks. Send back if not a fit. The alternative is a hatch transplant operation using the Sea-Lect 17-5/8 x 12-7/8 Hatch Cover and Ring Kit.
This Oval cover was common on Mainstream, Perception, Islander and Dagger kayaks circa 2000-2003, such as the Islander Encore, Mainstream Kingfish, Dagger Cayman and Perception Carolina. Was made of rubber, fit over the raised hatch opening like a Tupperware lid. Had an internal tie-off for a leash. Cover was 17.5 inches long by 12.5 inches wide outside dimensions. Inside dimensions where approximately 11.5 by 16.25 inches. It fit a rim slightly larger than the inside dimensions of the cover. If your 2000-2003 Dagger, Perception or Mainstream hatch cover was black rubber this was the correct hatch cover.
The classic 10 in. hatch cover by Perception (pre 2003), also a version bearing the Dagger logo, is likewise discontinued. The 24cm Kajak Sport hatch is considered the best replacement option, but you might try the modern Dual Density hatch covers bearing the Perception or Dagger logo, that are stiffer and less flexible. All of these would fit a hatch rim approximately 10 inches in diameter, when measured to the outside edge. Tip: measure both front to back and side to side of the round hatch lip.
See all Perception and Dagger rubber hatch options. PERDAGRH
Important Article: Kayak Hatch Replacement Options - Part I - Rubber Covers