... Sounds like wood is the way to go, thanks D’Arcy & Randy for the drawings. Yes, supporting the mast at the splice an excellent suggestion, so I’ll go with three struts/supports … also like the idea of a support through the mast partners, but also really like the idea of an “off-center” set-up in Jon’s photo. This system would be used only for one day, twice a year, for a +/- 8 hour all day motor. I shouldn’t see rough conditions, highly protected route, but there could be the large wake or two. Get the message on the lateral loads & support, and the fore & aft springs, thanks. Secure the mast to my stanchion plates all the way down with ratcheting straps, excellent photo, thanks Jon … like the temporary mast light stand too !

Thanks everyone once again for the excellent ideas, photos and drawings !

Cheers, John