We stayed at Tante Marta which is the cheapest option on the island (there are only 3 or 4 other options, the most expensive is Siladen Resort at around £200 per person per night, or mid range options like oongs for around 90 euros per person per night). our place, Tante marta was next to Siladen resort and so shared the best beach on the island (deep, soft sand that did not get entirely soaked at high tide so would always be soft in the mornings). Room was more basic than in bunaken, toilet was very very basic - western toilet bowl with no flush or seat and bucket and pail for showering and flushing. However given its so much cheaper it was worth it for us. On that note it was 200k Rp per person per night including 3 meals and water. The basic amenities were more than made up for by the warm welcome from tante marta (minimal english though!) and her husband and daughter who looked after us like we were part of the family, especially when one of us got very ill and she called the doctor and insisted paying for medication and prepared special meals. The other big draw is the fantastic sunsets over Manado Tuah which is directly in the line of sight and its easy to lose yourself in the sheer beauty of a wonderfully golden sunset that repeats itself every day over the supremely idyllic volcanic Tuah.
In terms of snorkelling, the coral is again very good, you need to go a little way out, but not more than 5 min swim straight out and you get to wonderful corals which fall away at the dropoff. Marine highlights were turtles, eels, cuttlefish, blue spotted rays and scorpion fishes and all the usuals from Bunaken but the best was a family of 4 bumphead parrotfish that were always found (well 4 days out of five) at the point where the sea grass meets the coral basically straight out from tante moon (which is the resort between Siladen resort and tante marta). Bear in mind all this marine life was simply from snorkeling, not diving. Other snorkleing spots are near the jetty where theres lots of life and if you hover under the jetty you will see some interesting macro life such as lots of lizard type fishes, scorpionfishes and eels.
Overall great location and friendly hosts. Rooms are budget and toilets basic but as long as you are prepared for this, it should be a great holiday