Hi Pavel,
I don't sail Severne but did find this below:
http://pdf.nauticexpo.com/pdf/severne-s ... 14883.htmlI realize your question is which of your masts do you use. I'll be brutal by saying I suspect all are very poor choices.
However, one may get you going, so if you're sticking with them, try so see what you like best.
I suggest if you're in it for the long term, do some research and keep an eye out for a proper mast. If you only sail a few times a year, then perhaps stick with what you have. If you plan for more, you may wonder down the road why you didn't improve your mast sooner.
My $100 3.7 was used only a few times a year so I used my 100% carbon 400. It worked but I started to strongly prefer my 4.5 (with the ideal 400 mast) even when well overpowered. Finally I got a 60% carbon powerex (cheap even new, probably near unbreakable). Total transformation for the 3.7. Significantly improved range and feel.
In my view, here is your priority:
1. Get the correct length and bend curve. The Severne brochure says 430. It does not state 400 or 460 as an alternative. It doesn't seem to specific RDM or SDM so you'd best look this up. You don't necessarily need to have a Severne mast. However, if you go another brand you need to confirm the bend curve. For example, I would think powerex or chinook may have an option, but I'd say confirm with them first
2. Carbon content. This matters little unless you get #1 correct. More the better but you can be very happy with less than 100% if you have #1 right. Mind you I've never heard of anyone today using an epoxy mast so I really can't say on this.
TMI? Either way, good luck!