not recommended but if time is really running out that what you'll have to do.
Important not to get too het up about antifouling - some people seem to treat it as though it's a force field or sealant where if there one tiny bit missing well then boatwill sink. But for an annually painted boat (or mostly annually) it doesn't matter if patches unpainted.
The bit you are putting paint on needs to be dry but a few spots running over newly applied paint never seems to hurt with solvent based paints. Don't try it with Optima which is water based! Lots of people antifoul cradle pad and keel bottom areas as the boat is launched and the boat goes in with the paint still wet, it still works and seems to stay put OK. I wouldn't do it for the whole hull however as that could prove messy and expensive if it did go pear shaped.
Don't worry about it, indeed, as the trend goes, you might find that at the end of the season, the patches of last years old stuff work better than this years new formula!!
If you are that bothered, dry a generous strip of topsides just above the waterline, and above the area you want to A/F. Apply a strip of masking tape, sticking the top edge on and leaving the bottom edge to hang off the hull. Hey-presto, drip strip, any errant rain running down will drip off allowing the hull patches to dry and be painted no-probs.
A few years ago I was up aginst the launch window in Brighton Marina. P*****g with rain for a week & lousy forecast. I did the masking tape bit but still needed to dry the underwater area & quick. I ended up hiring a gas blow torch from HSS, used the window squegee from the car to take the worst of the wet off, & the blow torch to warm & dry the hull before a/f application. It was a case of blow torch in left hand, paint roller in the right. A/f dried very quickly, being on a nice warm hull, so I just started at front & kept going until I had done 2 coats all round. More than somewhat knackered at the end of it, but job done. (and the paint stayed on for 2 seasons!)
Oh blimey, tell me about it!! Went down the boat to wack on the third coat of anti-fouling this morning, confident that despite the rain, with the boat inside a barn, there'd be no problems. /forums/images/graemlins/smile.gif
WRONG!!! /forums/images/graemlins/mad.gif The massive temperature change (warmer) during the night had made the boat positvely DRIP wit condensation! Wiped it all down, dabbed it with tissues, and bu*g*red around with fan heater for the best part of two hours before admitting defeat and going home! /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif