Russian 1987 Scuba Postal Card

Can someone who is able please be so kind as to decipher where in the USSR this postal card was mailed and anything else they might be able to translate into the Queen's English?

Registered letter from Leningrad.
On the big cancel : "Underwater Orientering World Championship" and "Leningrad Post Office"

The picture and fancy cancellation are for the (3rd) World Underwater Orienteering Championship, held in Leningrad in August 1987.
Harder to decipher the hand-written Russian script.

You're both the best. Thank you !!

I forgot to mention that the letter was addressed to Moscow (the first hand-written word is Moskva)

T#1086; be precise, it was addressed poste restante to the Main Post Office (Postamt) in Moscow, the addressee was S.Yu. Vasilieva.

The letter was paid to a correct registration rate - 10 kopecks for the internal registered letter them (5 kopecks the indicia of the cover - it's a prepaid cover, not a postcard, - plus an additional definitive 5-kopeck stamp).

The letter was sent on the last day of the championship, August 10.

Thanks everybody ! As usual, the collective knowledge on this message board is remarkable !

Sent registered (Zakasnoye) from Leningrad and sent to Moskow.
Worldchampoinship of some sort of diving. Hope that helps