One key word in your post 'similar' ... if boat isnt the same model with same design hull, same amount of water or fuel aboard and other kit etc etc etc then likely not to sit the same. Or it could be a slightly different tube design where the tubes sit slightly higher or maybe your tubes need inflating.
some ribs do sit lower than others by design, you may not have an issue at all, send some pics in, usually if something isnt right then it wont look right.
Normally majority of ribs sit with just the rear quarter maybe touching the water, scorpions defo sit higher than say cobras but again it may just be the tube postioning.
perhaps have a look round various marinas to see if you can spot an identical rib to yours.