I'm worried about the temperature.

[HanBan]

Hi Guys, I moved her back to the base last night. It was freezing out, but lovely to get out on her. We've winterized the freshwater systems with some potable antifreeze, and for the moment I've put an engine room heater on the engine...hopefully it'll work well enough for now. Sorry I haven't been replying as soon as I normally do, I'm gettin smashed with finals and research.
Happy Holiday and you guys are so freaking lovely!
Han

This is the engine room heater I'm using. https://www.amazon.com/gp/product/B00MEMRGZE/ref=od_aui_detailpages00?ie=UTF8&psc=1

 

[Ron20324]

I watch the Thomas Point lighthouse weather station year-round. It is in the open bay, near Annapolis. Last night it was 40.x. degrees. This morning it rose into the 41-degree range after sunrise. From the address below, you can probably find a NOAA reporting station nearer to you.
https://www.ndbc.noaa.gov/station_page.php?station=tplm2

 

[kappykaplan]

HanBan, here's the site for the Solomons Island reporting station: https://www.ndbc.noaa.gov/station_page.php?station=slim2

 

[BigEasy]

Hannah,
I have used a Caframo/West Marine ceramic heater on my boat for many years when temps drop into the 20's (rarely).
It has been reliable and trouble free. As I mentioned previously I only live 15 minutes from the boat; therefore, I can check on it and turn it on/off as needed for short durations.
While the Caframo engine room heater is a good short term solution for you, there are many on this site who frown on allowing electrical devices to run unattended for long periods of time and some marinas that forbid it. Not to mention the consequences when a storm drops temps into the low teens and power is lost. Down the stretch, it would likely be better to flush the raw water side of your engine with antifreeze so you don't have to worry about the engine during winter and avoid those 90 mile unexpected trips to the boat. Here are some bronze fittings from Groco, SSC and SSCV service adaptors, that simplify the process of winterizing your engine and yes, these can also be used as an emergency bilge pump if the need arises.
https://www.groco.net/products/valves-seacocks/accessories.