soft spots

Yes it is really that simple. Just work your way around the boat pushing on the hull every few inches. If you feel no motion it is probably solid. If the glass moves under you hands you are typically looking at a soft spot. If you hear anything crunch you are definitely looking at a spot in need of repair. Don't be gentle, the p18 is a tough boat and if you manage to break something checking for soft spots it was going to break anyway the first time you put the boat on the water.

they tend to be on the deck lids(top) of hulls, especially foreward of the crossbars where people have a tendancy to sit/stand...you will hear the "crunch" sound when you put some pressure on it. check the sides of the hulls too by pressing with your fingers all over it. these will give a hollow sound like a blister when you tap on them compared to the surrounding areas. it's not a difficult repair if you find some.

One more for the Prindle folks. Since I'm in the process of buying are P16's prone to having a common delam spot besides just fore of the crossbar?

It seems that most repairs I've seen have been to the top deck how common are delam issues on the vertical parts of the hull? Are the sides of the hull the same sandwich construction as the deck lid?

sides are foam core also...it useually takes a hard shot to the glass to make a delam on the sides but i have seen a few with huge delams on the exterior sides by the for crossbar...but these are super obvious. you will see some with wavey sides on the inside of the hulls, this is from being flipped a bunch and people standing/bouncing on them to right the boat, they may not be soft though, just "wavey".

Our P18 has some soft spots on the inside of the hull, so it definitely happens! They are just aft of the forward beam. about 3-5 inches lower then the hull lip. nice winter project...

The only soft spot on my '82 P18 were top of starboard hull between the front crossbar and the port.