winter storage and solar panels

Went to my boat today with my lovely daughter inlaw put antifreeze in and covered  the canopy with tarpaulin sheet my question is, I have two solar panels one on each battery the batteries are boxed in and difficult to get out will the solar panels be adequate to keep batteries charged up at the moment they read 12.5 volts after leaving them 4 weeks ago

A lot depends on your panel watts, but could be sufficient to keep them healthy if they start that way !  ( Again depends on the amount of available sunlight that will reach the panels) 
My starter battery seems to hold charge over winter ok with no Solar panel, l do take the leisure battery home though.

A fully charged battery will read 12.6V. If it is still being charged the figure could be up to 14V (sometimes higher depending on you set up)  What wattage are you solar panels?

The batteries were reading 12.6 volts the panels are 80 watts thanks for your info I have decided to attach automatic chargers to the batteries they are new just ordered and can be permanently attached

80 watts is more than enough to keep them topped up (hope you have a regulator fitted, to stop them overcharging).  I have a 30 watt panel permanently attached, which keeps my two 115 amp domestic batteries topped up during the winter.  The batteries have lasted 9 years so far - a record for me.  My previous batteries without a solar panel fitted lasted on average 5 years.

Yes Jim
           I have two regulators and they both constantly give the same reading on each battery the chargers are not expensive so if I keep a check every couple weeks and they do drop a little I can give a quick boost

So it looks like as long as your batteries are in good order - you should have no problems keeping them charged.  I'm still waiting for my boat to be craned out. Unless we get 2 or 3 weeks without rain, I cannot see us getting out this winter.

10 day forecast looks OK Jim

I think it could take more than 10 days, a lot of the fields are flooded up this end. Today the river is about 2" above our staging - that's over 3ft up .  We crane out around 50 boats and some have to come upstream from Eynsham.  All boards have been on red for the last 3 days. It's not looking good. If it comes up another 3ft I can float it onto the stands

I was close to floating off the stands yesterday, Avon peaked at 3.5 mtrs up at Evesham needed another 1.5 mtrs to beat 2007.