Sorry mate but that photo is just so cropped in & mostly blurry that I can't tell what the heck it is I'm looking at. Could be from the Mars probe for all I know. lol. Can you post a better pic? If you are getting water seeping in from a crack in the bilge that is serious however. If it opens up it could potentially sink your boat. The only way for water to rise up through a crack in the bilge, would mean that a large Catalina smile has developed to the point that it is leaking through the keel to hull joint. This will cause serious crevice corrosion, endagering your keel bolts & will surely saturate the plywood base that it under the keel bolts. Post another pic, but if your getting a measurable amount of water seeping in, & not a drip leak from your shaft seal, etc. then you should seriously consider a haul out to determine the extent of your problem. Have you run aground recently?