The ICON WT3855 fresh water tank you found, which measures approximately 50.75" x 22.75" x 5.75" and holds about 26.4 gallons, is not suitable for a Monaco Cayman 36 RV that requires a potable water tank with a capacity around 90 to 92 gallons. The original Monaco tank will be significantly larger, typically having greater depth or height dimensions to accommodate the higher volume.

To find the correct replacement, verify the actual physical dimensions of your original tank, including any unique shapes such as "L" or "T" configurations or additional risers. Providing a part number, label information, or photos of the original tank can greatly assist in identifying a compatible replacement.

Elkhart RV Parts carries larger capacity fresh water tanks closer to your needs, including ICON models with capacities around 43 gallons and a selection of 100-gallon tanks. With more detailed information about your original tank, we can help you locate the exact or closest compatible replacement to ensure your Monaco Cayman 36 maintains its full potable water capacity.