Hi Mike,
Welcome to the forum - that's a beautiful Black Sea yat...
With regards to the bayonets, I see, clockwise from the top-left, a Danish Mauser, a British P1888 (top-right), a British No. 4 spike bayonet (from WWII), and what appears to be a cruciform socket bayonet, which limits it to one of several patterns... Not sure which one exactly - it doesn't have the profile of a (Russian) Mosin Nagant socket bayonet... If you could post close-up pics of any stamps or marks on the last one, it would help.